diff --git a/src/browser/components/tabbrowser/content/tabbrowser-js.patch b/src/browser/components/tabbrowser/content/tabbrowser-js.patch
index 46fdcd3c5..c810f9de4 100644
--- a/src/browser/components/tabbrowser/content/tabbrowser-js.patch
+++ b/src/browser/components/tabbrowser/content/tabbrowser-js.patch
@@ -1,5 +1,5 @@
 diff --git a/browser/components/tabbrowser/content/tabbrowser.js b/browser/components/tabbrowser/content/tabbrowser.js
-index 3204f253c23551650991d3385dd256d55892a012..78727727a0c623e0213177700124869b2163b89c 100644
+index 3204f253c23551650991d3385dd256d55892a012..0285b0bcf1e5ba769011c82729e010eedf8dcc29 100644
 --- a/browser/components/tabbrowser/content/tabbrowser.js
 +++ b/browser/components/tabbrowser/content/tabbrowser.js
 @@ -427,15 +427,64 @@
@@ -804,7 +804,15 @@ index 3204f253c23551650991d3385dd256d55892a012..78727727a0c623e0213177700124869b
            window.focus();
            aEvent.preventDefault();
            break;
-@@ -8199,6 +8376,7 @@
+@@ -7264,7 +7441,6 @@
+         }
+         case "TabGroupCollapse":
+           aEvent.target.tabs.forEach(tab => {
+-            this.removeFromMultiSelectedTabs(tab);
+           });
+           break;
+         case "TabGroupCreateByUser":
+@@ -8199,6 +8375,7 @@
              aWebProgress.isTopLevel
            ) {
              this.mTab.setAttribute("busy", "true");
@@ -812,7 +820,7 @@ index 3204f253c23551650991d3385dd256d55892a012..78727727a0c623e0213177700124869b
              gBrowser._tabAttrModified(this.mTab, ["busy"]);
              this.mTab._notselectedsinceload = !this.mTab.selected;
            }
-@@ -9200,7 +9378,7 @@ var TabContextMenu = {
+@@ -9200,7 +9377,7 @@ var TabContextMenu = {
      );
      contextUnpinSelectedTabs.hidden =
        !this.contextTab.pinned || !this.multiselected;
@@ -821,7 +829,7 @@ index 3204f253c23551650991d3385dd256d55892a012..78727727a0c623e0213177700124869b
      // Build Ask Chat items
      TabContextMenu.GenAI.buildTabMenu(
        document.getElementById("context_askChat"),
-@@ -9520,6 +9698,7 @@ var TabContextMenu = {
+@@ -9520,6 +9697,7 @@ var TabContextMenu = {
          )
        );
      } else {
diff --git a/src/zen/common/styles/zen-single-components.css b/src/zen/common/styles/zen-single-components.css
index 9853a83da..e1599b51d 100644
--- a/src/zen/common/styles/zen-single-components.css
+++ b/src/zen/common/styles/zen-single-components.css
@@ -38,7 +38,7 @@ body > #confetti {
 }
 
 /* Bookmarks */
-#PersonalToolbar:not([collapsed='true']) {
+#PersonalToolbar:not([collapsed]) {
   min-height: 30px;
 }
 
diff --git a/src/zen/tabs/zen-tabs.css b/src/zen/tabs/zen-tabs.css
index 4319b3431..bfd25a1ff 100644
--- a/src/zen/tabs/zen-tabs.css
+++ b/src/zen/tabs/zen-tabs.css
@@ -36,7 +36,7 @@
       * - Bookmarks toolbar is visible OR
       * - The container is explicitly marked to hide controls (e.g., on Linux with reversed controls)
       */
-    &:has(#PersonalToolbar[collapsed='false']) {
+    &:has(#PersonalToolbar:not([collapsed])) {
 %include zen-tabs/vertical-tabs-topbar.inc.css
     }
     &[should-hide='true'] {
diff --git a/src/zen/tabs/zen-tabs/vertical-tabs-topbar.inc.css b/src/zen/tabs/zen-tabs/vertical-tabs-topbar.inc.css
index ac882b445..5bd8997da 100644
--- a/src/zen/tabs/zen-tabs/vertical-tabs-topbar.inc.css
+++ b/src/zen/tabs/zen-tabs/vertical-tabs-topbar.inc.css
@@ -43,7 +43,7 @@ z-index: 1;
   }
 
   @media -moz-pref('zen.view.experimental-no-window-controls') {
-    &:has(#PersonalToolbar[collapsed='true']) {
+    &:has(#PersonalToolbar[collapsed]) {
       max-height: 0 !important;
       overflow: hidden;
       opacity: 0 !important;
diff --git a/src/zen/tabs/zen-tabs/vertical-tabs.css b/src/zen/tabs/zen-tabs/vertical-tabs.css
index 5db51b127..853270d05 100644
--- a/src/zen/tabs/zen-tabs/vertical-tabs.css
+++ b/src/zen/tabs/zen-tabs/vertical-tabs.css
@@ -498,7 +498,7 @@
   padding-top: 0; /* Reset top padding */
 
   /* Ensure Personal Toolbar has no left padding when expanded */
-  #PersonalToolbar:not([collapsed='true']) {
+  #PersonalToolbar:not([collapsed]) {
     padding-left: 0 !important;
   }
 
diff --git a/src/zen/tests/folders/browser_folder_multiselected.js b/src/zen/tests/folders/browser_folder_multiselected.js
index 577c85a4c..39a0659c2 100644
--- a/src/zen/tests/folders/browser_folder_multiselected.js
+++ b/src/zen/tests/folders/browser_folder_multiselected.js
@@ -19,7 +19,7 @@ add_task(async function test_Folder_Multiselected_Tabs() {
   await collapseEvent;
 
   ok(tab2.multiselected, 'Tab 2 should not be multiselected');
-  Assert.equal(gBrowser.multiSelectedTabsCount, 2, 'There should be 2 multiselected tabs');
+  Assert.equal(gBrowser.multiSelectedTabsCount, 3, 'There should be 3 multiselected tabs');
 
   for (const t of [tab1, tab2]) {
     BrowserTestUtils.removeTab(t);