Sometimes it won’t let me (a TL4 and admin on my forum) to flag a chat message. Other Tl3s are also getting this issue. Though for some people it works fine. Is there a cause behind this?
We probably need more info to help you here. Can you provide more granular repro steps?
Side note, closing and re-opening the chat clears the bug for existing messages, though new ones after that exhibit the same behavior.