I have been curious about this for some time, or at least I think that I noticed it for the first time after the switch from Android 9 to Android 10. Like I said quite some time ago.
Does anyone know why Smart Lock is asking so often for Biometrics. At least it is not Smart Lock that is asking for it but my phone when I turn on the screen.
I have Smart Lock set up to use trusted devices, in other words if my galaxy watch is connected, it should stay unlocked. However it seems that doesn't stay unlocked at all and it is very frustrating.
I fully understand that after 4 hours of inactivity you have to use biometrics, and I am also aware that once every 24 hours you have to use biometrics. But what is happening is just so odd. It can ask for biometrics very randomly and sometimes with minutes between unlocks. Recently I started check my status bar to see if it shows bluetooth as connected to either my watch or my car, and it does.
I have had this issue with my S10 plus as well, and funny enough only on Android 10. On Android 9 it was working as I expected.
I hope someone else has experiences with it or even better a solution.