diff --git a/src/UniGetUI.Core.Tools.Tests/ToolsTests.cs b/src/UniGetUI.Core.Tools.Tests/ToolsTests.cs
index 965e2fc3a..7f66f0697 100644
--- a/src/UniGetUI.Core.Tools.Tests/ToolsTests.cs
+++ b/src/UniGetUI.Core.Tools.Tests/ToolsTests.cs
@@ -139,7 +139,7 @@ public void TestSafeQueryString(string query, string expected)
         }
 
         [Fact]
-        public void TestEnvVariables()
+        public void TestEnvVariableCreation()
         {
             const string ENV1 = "NONEXISTENTENVVARIABLE";
             Environment.SetEnvironmentVariable(ENV1, null, EnvironmentVariableTarget.Process);
@@ -160,5 +160,30 @@ public void TestEnvVariables()
             newInfo2.Environment.TryGetValue(ENV1, out string? result3);
             Assert.Null(result3);
         }
+
+        [Fact]
+        public void TestEnvVariableReplacement()
+        {
+            const string ENV = "TMP";
+
+            var expected = Environment.GetEnvironmentVariable(ENV, EnvironmentVariableTarget.User);
+
+            ProcessStartInfo info = CoreTools.UpdateEnvironmentVariables();
+            info.Environment.TryGetValue(ENV, out string? result);
+            Assert.Equal(expected, result);
+        }
+
+        [Fact]
+        public void TestEnvVariableYuxtaposition()
+        {
+            const string ENV = "PATH";
+
+            var oldpath = Environment.GetEnvironmentVariable(ENV, EnvironmentVariableTarget.Machine) + ";" +
+                          Environment.GetEnvironmentVariable(ENV, EnvironmentVariableTarget.User);
+
+            ProcessStartInfo info = CoreTools.UpdateEnvironmentVariables();
+            info.Environment.TryGetValue(ENV, out string? result);
+            Assert.Equal(oldpath, result);
+        }
     }
 }
diff --git a/src/UniGetUI.Core.Tools/Tools.cs b/src/UniGetUI.Core.Tools/Tools.cs
index 7f14277fb..43d5cc785 100644
--- a/src/UniGetUI.Core.Tools/Tools.cs
+++ b/src/UniGetUI.Core.Tools/Tools.cs
@@ -498,7 +498,16 @@ public static ProcessStartInfo UpdateEnvironmentVariables(ProcessStartInfo info)
             }
             foreach (DictionaryEntry env in Environment.GetEnvironmentVariables(EnvironmentVariableTarget.User))
             {
-                info.Environment[env.Key.ToString()] = env.Value?.ToString();
+                string key = env.Key.ToString() ?? "";
+                string newValue = env.Value?.ToString() ?? "";
+                if (info.Environment.TryGetValue(key, out string? oldValue) && oldValue is not null && oldValue.Contains(';') && newValue != "")
+                {
+                    info.Environment[key] = oldValue + ";" + newValue;
+                }
+                else
+                {
+                    info.Environment[key] = newValue;
+                }
             }
             return info;
         }
diff --git a/src/UniGetUI/Interface/SoftwarePages/AbstractPackagesPage.xaml.cs b/src/UniGetUI/Interface/SoftwarePages/AbstractPackagesPage.xaml.cs
index 7c3830b05..1ee939f80 100644
--- a/src/UniGetUI/Interface/SoftwarePages/AbstractPackagesPage.xaml.cs
+++ b/src/UniGetUI/Interface/SoftwarePages/AbstractPackagesPage.xaml.cs
@@ -487,7 +487,13 @@ public void FilterPackages()
                     }
                     else if (RootNodeForManager.ContainsValue(node))
                     {
-                        VisibleManagers.Add(RootNodeForManager.First(x => x.Value == node).Key);
+                        IPackageManager manager = RootNodeForManager.First(x => x.Value == node).Key;
+                        VisibleManagers.Add(manager);
+                        if (manager.Capabilities.SupportsCustomSources)
+                        {
+                            foreach (IManagerSource source in manager.SourceFactory.GetAvailableSources())
+                                if (!VisibleSources.Contains(source)) VisibleSources.Add(source);
+                        }
                     }
                 }
             }
@@ -568,8 +574,8 @@ public void FilterPackages()
             }
             FilteredPackages.BlockSorting = false;
             FilteredPackages.Sort();
-            PackageList.InvalidateArrange();
             UpdatePackageCount();
+            ForceRedrawByScroll();
         }
 
         /// <summary>
@@ -793,5 +799,15 @@ private void SelectAllCheckBox_ValueChanged(object sender, RoutedEventArgs e)
                 FilteredPackages.ClearSelection();
             }
         }
+
+        private async void ForceRedrawByScroll()
+        {
+            if (PackageList is not null)
+            {
+                PackageList.ScrollView?.ScrollTo(0, 1);
+                await Task.Delay(10);
+                PackageList.ScrollView?.ScrollTo(0, 0);
+            }
+        }
     }
 }