diff --git a/.gitattributes b/.gitattributes
index 91b0574a08..ff4e39cf72 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -3,7 +3,9 @@
 /.gitattributes export-ignore
 /.github export-ignore
 /.gitignore export-ignore
-/.php_cs.dist export-ignore
+/.phpcs.xml.dist export-ignore
+/.php-cs-fixer.dist.php export-ignore
+/.readthedocs.yaml export-ignore
 /.scrutinizer.yml export-ignore
 /CHANGELOG.PHPExcel.md export-ignore
 /bin export-ignore
@@ -11,6 +13,8 @@
 /docs export-ignore
 /infra export-ignore
 /mkdocs.yml export-ignore
+/phpstan.neon.dist export-ignore
+/phpstan-baseline.neon export-ignore
 /phpunit.xml.dist export-ignore
 /samples export-ignore
 /tests export-ignore
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8dea1f30a3..a04a802e13 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,11 +5,15 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com)
 and this project adheres to [Semantic Versioning](https://semver.org).
 
-## TBD - 2.1.5
+## 2024-12-08 - 2.1.5
 
 ### Fixed
 
 - Fix Minor Break Handling Drawings. Backport of [PR #4244](https://github.com/PHPOffice/PhpSpreadsheet/pull/4244)
+- Swapped Row and Column Indexes in Reference Helper. Backport of [PR #4247](https://github.com/PHPOffice/PhpSpreadsheet/pull/4247)
+- Upgrade locked version of Tcpdf (security advisory).
+- Upgrade locked version of Dompdf (Php8.4 compatibility).
+- Remove unnecessary files from Composer package.
 
 ## 2024-11-22 - 2.1.4
 
diff --git a/composer.json b/composer.json
index 5667818c86..74832919db 100644
--- a/composer.json
+++ b/composer.json
@@ -88,7 +88,7 @@
     },
     "require-dev": {
         "dealerdirect/phpcodesniffer-composer-installer": "dev-main",
-        "dompdf/dompdf": "^2.0",
+        "dompdf/dompdf": "^2.0 || ^3.0",
         "friendsofphp/php-cs-fixer": "^3.2",
         "mitoteam/jpgraph": "^10.3",
         "mpdf/mpdf": "^8.1.1",
diff --git a/composer.lock b/composer.lock
index 67afcd97ea..00e34f7d8f 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "b26a18ad03352af543e5cf686162fdbb",
+    "content-hash": "dba36d693d93eddd55314afd051fe473",
     "packages": [
         {
             "name": "maennchen/zipstream-php",
@@ -835,32 +835,34 @@
         },
         {
             "name": "dompdf/dompdf",
-            "version": "v2.0.8",
+            "version": "v3.0.1",
             "source": {
                 "type": "git",
                 "url": "https://github.com/dompdf/dompdf.git",
-                "reference": "c20247574601700e1f7c8dab39310fca1964dc52"
+                "reference": "2d622faf9aa1f8f7f24dd094e49b5cf6c0c5d4e6"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/dompdf/dompdf/zipball/c20247574601700e1f7c8dab39310fca1964dc52",
-                "reference": "c20247574601700e1f7c8dab39310fca1964dc52",
+                "url": "https://api.github.com/repos/dompdf/dompdf/zipball/2d622faf9aa1f8f7f24dd094e49b5cf6c0c5d4e6",
+                "reference": "2d622faf9aa1f8f7f24dd094e49b5cf6c0c5d4e6",
                 "shasum": ""
             },
             "require": {
+                "dompdf/php-font-lib": "^1.0.0",
+                "dompdf/php-svg-lib": "^1.0.0",
                 "ext-dom": "*",
                 "ext-mbstring": "*",
                 "masterminds/html5": "^2.0",
-                "phenx/php-font-lib": ">=0.5.4 <1.0.0",
-                "phenx/php-svg-lib": ">=0.5.2 <1.0.0",
                 "php": "^7.1 || ^8.0"
             },
             "require-dev": {
+                "ext-gd": "*",
                 "ext-json": "*",
                 "ext-zip": "*",
                 "mockery/mockery": "^1.3",
-                "phpunit/phpunit": "^7.5 || ^8 || ^9",
-                "squizlabs/php_codesniffer": "^3.5"
+                "phpunit/phpunit": "^7.5 || ^8 || ^9 || ^10",
+                "squizlabs/php_codesniffer": "^3.5",
+                "symfony/process": "^4.4 || ^5.4 || ^6.2 || ^7.0"
             },
             "suggest": {
                 "ext-gd": "Needed to process images",
@@ -891,9 +893,100 @@
             "homepage": "https://github.com/dompdf/dompdf",
             "support": {
                 "issues": "https://github.com/dompdf/dompdf/issues",
-                "source": "https://github.com/dompdf/dompdf/tree/v2.0.8"
+                "source": "https://github.com/dompdf/dompdf/tree/v3.0.1"
+            },
+            "time": "2024-12-05T14:59:38+00:00"
+        },
+        {
+            "name": "dompdf/php-font-lib",
+            "version": "1.0.1",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/dompdf/php-font-lib.git",
+                "reference": "6137b7d4232b7f16c882c75e4ca3991dbcf6fe2d"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/dompdf/php-font-lib/zipball/6137b7d4232b7f16c882c75e4ca3991dbcf6fe2d",
+                "reference": "6137b7d4232b7f16c882c75e4ca3991dbcf6fe2d",
+                "shasum": ""
+            },
+            "require": {
+                "ext-mbstring": "*",
+                "php": "^7.1 || ^8.0"
+            },
+            "require-dev": {
+                "symfony/phpunit-bridge": "^3 || ^4 || ^5 || ^6"
+            },
+            "type": "library",
+            "autoload": {
+                "psr-4": {
+                    "FontLib\\": "src/FontLib"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "LGPL-2.1-or-later"
+            ],
+            "authors": [
+                {
+                    "name": "The FontLib Community",
+                    "homepage": "https://github.com/dompdf/php-font-lib/blob/master/AUTHORS.md"
+                }
+            ],
+            "description": "A library to read, parse, export and make subsets of different types of font files.",
+            "homepage": "https://github.com/dompdf/php-font-lib",
+            "support": {
+                "issues": "https://github.com/dompdf/php-font-lib/issues",
+                "source": "https://github.com/dompdf/php-font-lib/tree/1.0.1"
+            },
+            "time": "2024-12-02T14:37:59+00:00"
+        },
+        {
+            "name": "dompdf/php-svg-lib",
+            "version": "1.0.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/dompdf/php-svg-lib.git",
+                "reference": "eb045e518185298eb6ff8d80d0d0c6b17aecd9af"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/dompdf/php-svg-lib/zipball/eb045e518185298eb6ff8d80d0d0c6b17aecd9af",
+                "reference": "eb045e518185298eb6ff8d80d0d0c6b17aecd9af",
+                "shasum": ""
+            },
+            "require": {
+                "ext-mbstring": "*",
+                "php": "^7.1 || ^8.0",
+                "sabberworm/php-css-parser": "^8.4"
+            },
+            "require-dev": {
+                "phpunit/phpunit": "^7.5 || ^8.5 || ^9.5"
+            },
+            "type": "library",
+            "autoload": {
+                "psr-4": {
+                    "Svg\\": "src/Svg"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "LGPL-3.0-or-later"
+            ],
+            "authors": [
+                {
+                    "name": "The SvgLib Community",
+                    "homepage": "https://github.com/dompdf/php-svg-lib/blob/master/AUTHORS.md"
+                }
+            ],
+            "description": "A library to read, parse and export to PDF SVG files.",
+            "homepage": "https://github.com/dompdf/php-svg-lib",
+            "support": {
+                "issues": "https://github.com/dompdf/php-svg-lib/issues",
+                "source": "https://github.com/dompdf/php-svg-lib/tree/1.0.0"
             },
-            "time": "2024-04-29T13:06:17+00:00"
+            "time": "2024-04-29T13:26:35+00:00"
         },
         {
             "name": "friendsofphp/php-cs-fixer",
@@ -1561,96 +1654,6 @@
             },
             "time": "2022-02-21T01:04:05+00:00"
         },
-        {
-            "name": "phenx/php-font-lib",
-            "version": "0.5.6",
-            "source": {
-                "type": "git",
-                "url": "https://github.com/dompdf/php-font-lib.git",
-                "reference": "a1681e9793040740a405ac5b189275059e2a9863"
-            },
-            "dist": {
-                "type": "zip",
-                "url": "https://api.github.com/repos/dompdf/php-font-lib/zipball/a1681e9793040740a405ac5b189275059e2a9863",
-                "reference": "a1681e9793040740a405ac5b189275059e2a9863",
-                "shasum": ""
-            },
-            "require": {
-                "ext-mbstring": "*"
-            },
-            "require-dev": {
-                "symfony/phpunit-bridge": "^3 || ^4 || ^5 || ^6"
-            },
-            "type": "library",
-            "autoload": {
-                "psr-4": {
-                    "FontLib\\": "src/FontLib"
-                }
-            },
-            "notification-url": "https://packagist.org/downloads/",
-            "license": [
-                "LGPL-2.1-or-later"
-            ],
-            "authors": [
-                {
-                    "name": "Fabien Ménager",
-                    "email": "fabien.menager@gmail.com"
-                }
-            ],
-            "description": "A library to read, parse, export and make subsets of different types of font files.",
-            "homepage": "https://github.com/PhenX/php-font-lib",
-            "support": {
-                "issues": "https://github.com/dompdf/php-font-lib/issues",
-                "source": "https://github.com/dompdf/php-font-lib/tree/0.5.6"
-            },
-            "time": "2024-01-29T14:45:26+00:00"
-        },
-        {
-            "name": "phenx/php-svg-lib",
-            "version": "0.5.4",
-            "source": {
-                "type": "git",
-                "url": "https://github.com/dompdf/php-svg-lib.git",
-                "reference": "46b25da81613a9cf43c83b2a8c2c1bdab27df691"
-            },
-            "dist": {
-                "type": "zip",
-                "url": "https://api.github.com/repos/dompdf/php-svg-lib/zipball/46b25da81613a9cf43c83b2a8c2c1bdab27df691",
-                "reference": "46b25da81613a9cf43c83b2a8c2c1bdab27df691",
-                "shasum": ""
-            },
-            "require": {
-                "ext-mbstring": "*",
-                "php": "^7.1 || ^8.0",
-                "sabberworm/php-css-parser": "^8.4"
-            },
-            "require-dev": {
-                "phpunit/phpunit": "^7.5 || ^8.5 || ^9.5"
-            },
-            "type": "library",
-            "autoload": {
-                "psr-4": {
-                    "Svg\\": "src/Svg"
-                }
-            },
-            "notification-url": "https://packagist.org/downloads/",
-            "license": [
-                "LGPL-3.0-or-later"
-            ],
-            "authors": [
-                {
-                    "name": "Fabien Ménager",
-                    "email": "fabien.menager@gmail.com"
-                }
-            ],
-            "description": "A library to read, parse and export to PDF SVG files.",
-            "homepage": "https://github.com/PhenX/php-svg-lib",
-            "support": {
-                "issues": "https://github.com/dompdf/php-svg-lib/issues",
-                "source": "https://github.com/dompdf/php-svg-lib/tree/0.5.4"
-            },
-            "time": "2024-04-08T12:52:34+00:00"
-        },
         {
             "name": "phpcompatibility/php-compatibility",
             "version": "9.3.5",
@@ -4860,16 +4863,16 @@
         },
         {
             "name": "tecnickcom/tcpdf",
-            "version": "6.7.5",
+            "version": "6.7.7",
             "source": {
                 "type": "git",
                 "url": "https://github.com/tecnickcom/TCPDF.git",
-                "reference": "951eabf0338ec2522bd0d5d9c79b08a3a3d36b36"
+                "reference": "cfbc0028cc23f057f2baf9e73bdc238153c22086"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/tecnickcom/TCPDF/zipball/951eabf0338ec2522bd0d5d9c79b08a3a3d36b36",
-                "reference": "951eabf0338ec2522bd0d5d9c79b08a3a3d36b36",
+                "url": "https://api.github.com/repos/tecnickcom/TCPDF/zipball/cfbc0028cc23f057f2baf9e73bdc238153c22086",
+                "reference": "cfbc0028cc23f057f2baf9e73bdc238153c22086",
                 "shasum": ""
             },
             "require": {
@@ -4920,7 +4923,7 @@
             ],
             "support": {
                 "issues": "https://github.com/tecnickcom/TCPDF/issues",
-                "source": "https://github.com/tecnickcom/TCPDF/tree/6.7.5"
+                "source": "https://github.com/tecnickcom/TCPDF/tree/6.7.7"
             },
             "funding": [
                 {
@@ -4928,7 +4931,7 @@
                     "type": "custom"
                 }
             ],
-            "time": "2024-04-20T17:25:10+00:00"
+            "time": "2024-10-26T12:15:02+00:00"
         },
         {
             "name": "theseer/tokenizer",
diff --git a/src/PhpSpreadsheet/Helper/Sample.php b/src/PhpSpreadsheet/Helper/Sample.php
index e0d2cfee24..c772aface1 100644
--- a/src/PhpSpreadsheet/Helper/Sample.php
+++ b/src/PhpSpreadsheet/Helper/Sample.php
@@ -9,7 +9,6 @@
 use PhpOffice\PhpSpreadsheet\Spreadsheet;
 use PhpOffice\PhpSpreadsheet\Worksheet\Worksheet;
 use PhpOffice\PhpSpreadsheet\Writer\IWriter;
-use PhpOffice\PhpSpreadsheet\Writer\Pdf\Dompdf;
 use RecursiveDirectoryIterator;
 use RecursiveIteratorIterator;
 use RecursiveRegexIterator;
@@ -130,11 +129,7 @@ public function write(Spreadsheet $spreadsheet, string $filename, array $writers
                 $writerCallback($writer);
             }
             $callStartTime = microtime(true);
-            if (PHP_VERSION_ID >= 80400 && $writer instanceof Dompdf) {
-                @$writer->save($path);
-            } else {
-                $writer->save($path);
-            }
+            $writer->save($path);
             $this->logWrite($writer, $path, $callStartTime);
             if ($this->isCli() === false) {
                 // @codeCoverageIgnoreStart
diff --git a/src/PhpSpreadsheet/ReferenceHelper.php b/src/PhpSpreadsheet/ReferenceHelper.php
index de9c3f25d3..acc5e5dbb9 100644
--- a/src/PhpSpreadsheet/ReferenceHelper.php
+++ b/src/PhpSpreadsheet/ReferenceHelper.php
@@ -1217,7 +1217,7 @@ private function duplicateStylesByRow(Worksheet $worksheet, int $beforeColumn, i
             if ($worksheet->cellExists($coordinate)) {
                 $xfIndex = $worksheet->getCell($coordinate)->getXfIndex();
                 for ($j = $beforeRow; $j <= $beforeRow - 1 + $numberOfRows; ++$j) {
-                    if (!empty($xfIndex) || $worksheet->cellExists([$j, $i])) {
+                    if (!empty($xfIndex) || $worksheet->cellExists([$i, $j])) {
                         $worksheet->getCell(Coordinate::stringFromColumnIndex($i) . $j)->setXfIndex($xfIndex);
                     }
                 }
diff --git a/tests/PhpSpreadsheetTests/Functional/StreamTest.php b/tests/PhpSpreadsheetTests/Functional/StreamTest.php
index c67c1ab22c..3430b7a31b 100644
--- a/tests/PhpSpreadsheetTests/Functional/StreamTest.php
+++ b/tests/PhpSpreadsheetTests/Functional/StreamTest.php
@@ -8,12 +8,6 @@
 use PhpOffice\PhpSpreadsheet\Spreadsheet;
 use PHPUnit\Framework\TestCase;
 
-/**
- * Not clear that Dompdf will be Php8.4 compatible in time.
- * Run in separate process and add version test till it is ready.
- *
- * @runTestsInSeparateProcesses
- */
 class StreamTest extends TestCase
 {
     public static function providerFormats(): array
@@ -48,11 +42,7 @@ public function testAllWritersCanWriteToStream(string $format): void
         } else {
             self::assertSame(0, $stat['size']);
 
-            if ($format === 'Dompdf' && PHP_VERSION_ID >= 80400) {
-                @$writer->save($stream);
-            } else {
-                $writer->save($stream);
-            }
+            $writer->save($stream);
 
             self::assertIsResource($stream, 'should not close the stream for further usage out of PhpSpreadsheet');
             $stat = fstat($stream);
diff --git a/tests/PhpSpreadsheetTests/ReferenceHelper5Test.php b/tests/PhpSpreadsheetTests/ReferenceHelper5Test.php
new file mode 100644
index 0000000000..bdb658896e
--- /dev/null
+++ b/tests/PhpSpreadsheetTests/ReferenceHelper5Test.php
@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpOffice\PhpSpreadsheetTests;
+
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PHPUnit\Framework\TestCase;
+
+class ReferenceHelper5Test extends TestCase
+{
+    public function testIssue4246(): void
+    {
+        // code below would have thrown exception because
+        // row and column were swapped in code
+        $spreadsheet = new Spreadsheet();
+        $sheet = $spreadsheet->getActiveSheet();
+        $row = 987654;
+        $rowMinus1 = $row - 1;
+        $rowPlus1 = $row + 1;
+        $sheet->getCell("A$rowMinus1")->setValue(1);
+        $sheet->getCell("B$rowMinus1")->setValue(2);
+        $sheet->getCell("C$rowMinus1")->setValue(3);
+        $sheet->getStyle("A$rowMinus1")->getFont()->setBold(true);
+        $sheet->getCell("A$row")->setValue(1);
+        $sheet->getCell("B$row")->setValue(2);
+        $sheet->getCell("C$row")->setValue(3);
+        $sheet->getStyle("B$row")->getFont()->setBold(true);
+
+        $sheet->insertNewRowBefore($row);
+        self::assertTrue(
+            $sheet->getStyle("A$row")->getFont()->getBold()
+        );
+        self::assertFalse(
+            $sheet->getStyle("B$row")->getFont()->getBold()
+        );
+        self::assertFalse(
+            $sheet->getStyle("A$rowPlus1")->getFont()->getBold()
+        );
+        self::assertTrue(
+            $sheet->getStyle("B$rowPlus1")->getFont()->getBold()
+        );
+        $spreadsheet->disconnectWorksheets();
+    }
+}
diff --git a/tests/PhpSpreadsheetTests/Writer/Dompdf/PaperSizeArrayTest.php b/tests/PhpSpreadsheetTests/Writer/Dompdf/PaperSizeArrayTest.php
index ccd0e84f05..4c0b86b637 100644
--- a/tests/PhpSpreadsheetTests/Writer/Dompdf/PaperSizeArrayTest.php
+++ b/tests/PhpSpreadsheetTests/Writer/Dompdf/PaperSizeArrayTest.php
@@ -10,12 +10,6 @@
 use PhpOffice\PhpSpreadsheet\Writer\Pdf\Dompdf;
 use PHPUnit\Framework\TestCase;
 
-/**
- * Not clear that Dompdf will be Php8.4 compatible in time.
- * Run in separate process and add version test till it is ready.
- *
- * @runTestsInSeparateProcesses
- */
 class PaperSizeArrayTest extends TestCase
 {
     private string $outfile = '';
@@ -42,11 +36,7 @@ public function testPaperSizeArray(): void
         $sheet->setCellValue('A7', 'Lorem Ipsum');
         $writer = new Dompdf($spreadsheet);
         $this->outfile = File::temporaryFilename();
-        if (PHP_VERSION_ID >= 80400) { // hopefully temporary
-            @$writer->save($this->outfile);
-        } else {
-            $writer->save($this->outfile);
-        }
+        $writer->save($this->outfile);
         $spreadsheet->disconnectWorksheets();
         unset($spreadsheet);
         $contents = file_get_contents($this->outfile);
@@ -66,11 +56,7 @@ public function testPaperSizeNotArray(): void
         $sheet->setCellValue('A7', 'Lorem Ipsum');
         $writer = new Dompdf($spreadsheet);
         $this->outfile = File::temporaryFilename();
-        if (PHP_VERSION_ID >= 80400) { // hopefully temporary
-            @$writer->save($this->outfile);
-        } else {
-            $writer->save($this->outfile);
-        }
+        $writer->save($this->outfile);
         $spreadsheet->disconnectWorksheets();
         unset($spreadsheet);
         $contents = file_get_contents($this->outfile);