Similar issue but not related to biometrics. This bug must be more than that.
Have a pixel 7, fully updated - I do not use any lock, just swipe to unlock the owner profile
Issue:
I just created a new second profile (first time ever on this phone) with a pin lock on that profile. The new second profile has a default everything, including lock screen (really big clock split into two hemispheres) Point being, when I switch back to the owner profile, it carries over the lock screen look and feel of the second profile. It stays this way until I reboot the phone. Then the owner profile goes back to my personal settings (little clock, etc)
100% happens every time.