Mac starts up, chime sounds, login screen opens. I click my account picture and enter the 100% correct password. The screen goes black leaving just the mouse on the screen, and the password screen pops back up. Repeats no matter how many times I try and is persistent after a reboot. Reported to apple, with a video attached but just want to warn people to remember that beta software can do this and to keep everything backed up, as I know some people have important stuff on their computers and don't backup!