Running VMWare Fusion 12.1.2 on Big Sur 11.4, I noticed since my iMac crashed yesterday and rebooted this problem when launching Fusion (although it may be unrelated): Fusion starts normally, Windows log in page loads but when I click on it, the pop up to enter my PIN no longer appears.
I noticed it takes about 15 seconds for the date & time to pop up on the bottom left corner which is slower than it used to. I also noticed that when I click on the page attempting to get to the pop up to enter my PIN, about a minute later, date & time comes back returning to the log in entry screen.
Long story short, I'm stuck at the front door.