I did some tests tonight. In that thread, there are two messages not created by you. One is unmarked. On that one, when I simulate other your account, I have the ability to mark the message as a help. On the other one, if I test as if no solution would have been given, I have the ability to mark the message as a help as well. Everything works as expected. This routine remained unchanged since a year now.

If you can simulate that again, I would be happy to do more tests.