Since this, update, fingerprints have been broken for me whenever I switch users on my Pixel 8a. Previously, going to another user and then returning to the main user would require me to use the pin code once to unlock fingerprint unlock on later attempts.
Now fingerprint unlock is completely broken upon switching users. If I switch out of the main user and switch back, the fingerprint unlock stops working entirely. In order to enable fingerprint unlock again, I have to go to the lock scren settings and toggle the option to use fingerprint for screen unlock off and on again.