I sent a message to the group that the Release of Bullseye has two big problems.
1.) You cannot log into MATE as a regular user.
2.) The sound card detection and selection dialog is broken because there is no sound to hear to verify which sound card works. If you know they your sound card is the last one detected, just wait a few seconds and press enter. You'll have to finish the accessible installation WITHOUT sound but when you boot up you'll have sound.
But you cannot log into MATE, you can type your username and password, press enter, but something crashes and you return to the put in your username step and it's an infinite loop, happening over and over if you type in the information.
You can go to console 2 and use the computer as a command line computer, it will be connected to the connection you used to install.
But GUI doesn't work as a regular user.
Something similar happened with the release of Buster several years ago, but the next released version fixed it.
Wait for the next version, hopefully the next version will fix this problem.
Best wishes,
David