Could it be something like
https://discussion.fedoraproject.org/t/registration-difficulties-on-chat-...
TLDR: matrix is supposed to show you a 'agreement' thing when you first
login to accept, somehow for this other user it got in a weird state
where they were not able to accept it or do anything else because it
wanted them to accept first.
If thats the case, I can ask our matirx contacts to fix your account.
I suppose also you could make a new account and try with it to confirm
you get the agreement and things work with it?
kevin