Jitsi doesn't work for me on MacOS 11.6.4 with Firefox 97.0.2

Just got invited to a meeting on Jitsi. I use Firefox on MacOS. The login screen came up, but then turned solid gray before I could respond and login. Any idea what I’ve done wrong? I then tried it on Safari and the login worked, but it behaved very weirdly, no audio with occasional strange roaring sounds.