diff --git a/src/components/shared/FullscreenElement/FullscreenElement.tsx b/src/components/shared/FullscreenElement/FullscreenElement.tsx
index 17bbe9d39..52d974ed5 100644
--- a/src/components/shared/FullscreenElement/FullscreenElement.tsx
+++ b/src/components/shared/FullscreenElement/FullscreenElement.tsx
@@ -53,6 +53,17 @@ function FullscreenElementPortal({
     };
   }, [fullscreen, defaultMountElement]);
 
+  // When fullscreen, stop keyboard events from reaching document-level listeners
+  // (e.g. ContextPanelProvider's Escape handler that would clear the panel and
+  // unmount this component's parent).
+  useEffect(() => {
+    if (!fullscreen) return;
+    const container = containerElementRef.current;
+    const stopPropagation = (e: KeyboardEvent) => e.stopPropagation();
+    container.addEventListener("keydown", stopPropagation);
+    return () => container.removeEventListener("keydown", stopPropagation);
+  }, [fullscreen]);
+
   return createPortal(<>{children}</>, containerElementRef.current, id.current);
 }
 
diff --git a/src/components/ui/dialog.tsx b/src/components/ui/dialog.tsx
index 98b124981..2e673e052 100644
--- a/src/components/ui/dialog.tsx
+++ b/src/components/ui/dialog.tsx
@@ -86,6 +86,7 @@ function DialogContent({
           className,
         )}
         onKeyDown={handleKeyDown}
+        onFocusOutside={(e) => e.preventDefault()}
         {...props}
       >
         {children}