The issue I had was staying logged in. I got my SSO to login by attending a meeting via the meeting ID and then logged out of the meeting and then was able to select the domain. Once I went to something g else though, (tesla map, etc, it would log me out so I gave up trying after that.
Setup a meeting and then manually type in the meeting ID and PW, then join the meeting and then exit the meeting and your SSO stuff should work after that.
Out Zoom is fedramp and I was able to select it right after the meeting *if* I don’t go to anything other Tesla apps. As soon as I do, it resets to the default Zoom options and back to square one.