diff --git a/packages/perspective-viewer-datagrid/src/js/plugin/activate.js b/packages/perspective-viewer-datagrid/src/js/plugin/activate.js
index dbb5faf8ea..86fd47292b 100644
--- a/packages/perspective-viewer-datagrid/src/js/plugin/activate.js
+++ b/packages/perspective-viewer-datagrid/src/js/plugin/activate.js
@@ -160,17 +160,20 @@ export async function activate(view) {
         viewer.addEventListener(
             "perspective-toggle-column-settings",
             (event) => {
-                style_selected_column(
-                    this.regular_table,
-                    event.detail.column_name
-                );
-                if (!event.detail.open) {
-                    this.model._column_settings_selected_column = null;
-                    return;
+                // NOTE: This is a hack. We'll need to implement a `deactivate` function on the API to properly remove this eventlistener.
+                if (this.isConnected) {
+                    style_selected_column(
+                        this.regular_table,
+                        event.detail.column_name
+                    );
+                    if (!event.detail.open) {
+                        this.model._column_settings_selected_column = null;
+                        return;
+                    }
+
+                    this.model._column_settings_selected_column =
+                        event.detail.column_name;
                 }
-
-                this.model._column_settings_selected_column =
-                    event.detail.column_name;
             }
         );
 
diff --git a/rust/perspective-viewer/src/less/containers/split-panel.less b/rust/perspective-viewer/src/less/containers/split-panel.less
index 3e220cacc5..888734fc19 100644
--- a/rust/perspective-viewer/src/less/containers/split-panel.less
+++ b/rust/perspective-viewer/src/less/containers/split-panel.less
@@ -11,7 +11,8 @@
 // ┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
 
 :host {
-    .split-panel.orient-reverse > .split-panel-child:not(:last-child):not(.is-width-override) {
+    .split-panel.orient-reverse
+        > .split-panel-child:not(:last-child):not(.is-width-override) {
         max-width: 300px;
     }
 
@@ -52,7 +53,7 @@
         .split-panel-divider {
             flex: 0 0 6px;
             transition: background-color 0.2s ease-out;
-            z-index: 2;
+            z-index: var(--settings-panel-z-index);
 
             &:hover {
                 background-color: rgba(0, 0, 0, 0.05);
diff --git a/rust/perspective-viewer/src/less/viewer.less b/rust/perspective-viewer/src/less/viewer.less
index 2913c2dec8..f5808d1338 100644
--- a/rust/perspective-viewer/src/less/viewer.less
+++ b/rust/perspective-viewer/src/less/viewer.less
@@ -10,6 +10,10 @@
 // ┃ of the [Apache License 2.0](https://www.apache.org/licenses/LICENSE-2.0). ┃
 // ┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
 
+:host {
+    --settings-panel-z-index: 10;
+}
+
 :host .sidebar_close_button {
     position: absolute;
     top: 0;
@@ -132,6 +136,7 @@
         padding-left: 8px;
         box-sizing: border-box;
         width: 100%;
+        z-index: var(--settings-panel-z-index);
 
         & > .split-panel-child {
             overflow: hidden;
@@ -301,6 +306,8 @@
         width: 100%;
         background-color: var(--inactive--color, #6e6e6e);
         margin-top: 1px;
+        flex-shrink: 0;
+        flex-grow: 0;
     }
 
     .expr_editor_column,