For what it's worth, I have also been experiencing this bug for some time now on a Pixel 7. Like OP said, an effective, albeit annoying, workaround is to go to:
Settings > Security > Fingerprint Unlock > Input your PIN/Password > Allow fingerprint unlocking > Toggle OFF > Toggle back to ON
I regularly utilize a second profile so I have to do the above frequently. I'm hoping Google addresses this issue soon.