maybe fix?

panel/tests/chat/test_feed.py

@@ -1098,6 +1098,16 @@ def callback(msg, user, instance):
         chat_feed.send("Message", respond=True)
         await async_wait_until(lambda: len(chat_feed.objects) == 1)
 
+    def test_callback_exception_raise(self, chat_feed):
+        def callback(msg, user, instance):
+            return 1 / 0
+
+        chat_feed.callback = callback
+        chat_feed.callback_exception = "raise"
+        with pytest.raises(ZeroDivisionError, match="division by zero"):
+            chat_feed.send("Message", respond=True)
+        wait_until(lambda: len(chat_feed.objects) == 1)
+
     async def test_callback_exception_callable(self, chat_feed):
         def callback(msg, user, instance):
             raise ValueError("Expected error")
@@ -1108,7 +1118,7 @@ def exception_callback(exception, instance):
         chat_feed.callback = callback
         chat_feed.callback_exception = exception_callback
         chat_feed.send("Message", respond=True)
-        wait_until(lambda: len(chat_feed.objects) == 2)
+        await async_wait_until(lambda: len(chat_feed.objects) == 2)
         assert chat_feed.objects[-1].object == "The exception: Expected error"
 
     def test_callback_exception_invalid_option(self, chat_feed):