I did try this anonymous room but it fails on Firefox on Linux. Example: https://firstname.lastname@example.org?nick=erwanguorg
The anonymous stuff only works for chatrooms hosted on our server, such as: https://email@example.com
If we allowed anonymous users out into the federation, we could become quite the source for SPAM unless additional measures were taken.
Thanks for the info! Maybe it could be better to spell it out explicitly either on welcome screen or when the connection fails? Because it looks quite broken from the initial impression.