diff --git a/lib/web_ui/lib/src/engine/pointer_binding.dart b/lib/web_ui/lib/src/engine/pointer_binding.dart
index c3ba7524a440d..af024173ebfa1 100644
--- a/lib/web_ui/lib/src/engine/pointer_binding.dart
+++ b/lib/web_ui/lib/src/engine/pointer_binding.dart
@@ -690,6 +690,7 @@ class _PointerAdapter extends _BaseAdapter with _WheelEventListenerMixin {
       }
     }, useCapture: false, checkModifiers: false);
 
+    // TODO(dit): This must happen in the glassPane, https://github.com/flutter/flutter/issues/116561
     _addPointerEventListener(domWindow, 'pointerup', (DomPointerEvent event) {
       final int device = _getPointerId(event);
       if (_hasSanitizer(device)) {
@@ -703,6 +704,8 @@ class _PointerAdapter extends _BaseAdapter with _WheelEventListenerMixin {
       }
     });
 
+    // TODO(dit): Synthesize a "cancel" event when 'pointerup' happens outside of the glassPane, https://github.com/flutter/flutter/issues/116561
+
     // A browser fires cancel event if it concludes the pointer will no longer
     // be able to generate events (example: device is deactivated)
     _addPointerEventListener(glassPaneElement, 'pointercancel', (DomPointerEvent event) {
@@ -1039,6 +1042,7 @@ class _MouseAdapter extends _BaseAdapter with _WheelEventListenerMixin {
       }
     }, useCapture: false);
 
+    // TODO(dit): This must happen in the glassPane, https://github.com/flutter/flutter/issues/116561
     _addMouseEventListener(domWindow, 'mouseup', (DomMouseEvent event) {
       final List<ui.PointerData> pointerData = <ui.PointerData>[];
       final _SanitizedDetails? sanitizedDetails = _sanitizer.sanitizeUpEvent(buttons: event.buttons?.toInt());
diff --git a/lib/web_ui/test/engine/pointer_binding_test.dart b/lib/web_ui/test/engine/pointer_binding_test.dart
index 3c2c4b225c6ce..3ffcd33a350c3 100644
--- a/lib/web_ui/test/engine/pointer_binding_test.dart
+++ b/lib/web_ui/test/engine/pointer_binding_test.dart
@@ -23,13 +23,15 @@ typedef _ContextTestBody<T> = void Function(T);
 void _testEach<T extends _BasicEventContext>(
   Iterable<T> contexts,
   String description,
-  _ContextTestBody<T> body,
+  _ContextTestBody<T> body, {
+    Object? skip,
+  }
 ) {
   for (final T context in contexts) {
     if (context.isSupported) {
       test('${context.name} $description', () {
         body(context);
-      });
+      }, skip: skip);
     }
   }
 }
@@ -867,6 +869,7 @@ void testMain() {
 
       semanticsPlaceholder.remove();
     },
+    skip: isFirefox, // https://bugzilla.mozilla.org/show_bug.cgi?id=1804190
   );
 
   // BUTTONED ADAPTERS
@@ -2263,7 +2266,7 @@ void testMain() {
       packets.clear();
 
       // Release outside the glasspane.
-      domWindow.dispatchEvent(context.primaryUp(
+      glassPane.dispatchEvent(context.primaryUp(
         clientX: 1000.0,
         clientY: 2000.0,
       ));
@@ -3328,6 +3331,7 @@ class _PointerEventContext extends _BasicEventContext
     String? pointerType,
   }) {
     return createDomPointerEvent('pointerup', <String, dynamic>{
+      'bubbles': true,
       'pointerId': pointer,
       'button': button,
       'buttons': buttons,