Same here, but chrome works.
I'm not sure it's a point lock issues, since that's supposed to work on FF.
In console, the difference I noticed is that FF has this error:
Firefox can't establish a connection to the server at ws://./. - shoote...tBqO.js (line 57)
What specifically doesn't work? Do they not render (WebGL issue) or does your pointer not get locked (Pointer Lock issue)? Try googling "firefox pointer lock doesn't work", I'm sure something relevant will come up.