Help S21 FE Fingerprint problems

[Sanadel]

I set the phone for fingerprint to be active even with display off, so i can unlock my phone without lit my screen,
Randomly, every 20-30 times maybe, fingerprint icon will not lit when i touch it. So i have to turn on display and after this i can unlock with fingerprint. After this again i can unlock my phone with fingerprint with display off, for another 20-30 times.

I try to turn off adaptive battery, no result same problem occur. No other power savings active, by my knowldge at least
I try to reset figerprint by removing and add again. No result. But this not a problem of recognition, my sensor for fingerprint will not lit when i touch. I also perform a clear cahce in ecovery mode. Im on android 13, and maybe this problem comes with this update. The phone works fine for few months and suddendy this problem, cant say if this occur with android 13 update o r few days early on android 12

 

[nickdalzell]

Samsung enforces the use of your alternative unlock method (PIN, pattern, or password) after some time, usually 4 hours. That's for additional security as biometric unlock isn't fully secure.

 

[Sanadel]

Nope. When i turn on the screen this allow me to unlock with my fingerprint, without asking any pin, pattern or password.
Problem is : when i touch the screen nothing happens, fingerprint sensor will not lit. I i turn on the screen, even if turn off after, then i touch the screen and i can unlock with my fingerprint just.
Sometimes the sensor will not respond to read when i touch screen. Like i have no fingerprint sensor, like is dead, nothing happen until i turn on the screen. After this will again work as should for a while

I try to be clear.
I have the screen off. I touch the screen, fingerprint sensor will lit and will un lock my phone. But sometimes touching the screen, wich is off, will not lit the sensor and sure will not unlock. But if i turn on the screen, with power key, and wait for screen to go off than i can touch again the screen, the sensor will lit and read my fingerprint and unkock my phone. Did i make myself clear ?