after update to OneUI 5.1 my fingerprint sensor stopped working at random times. it fixed after couple of restarts. but after the recent security update, it stopped working and no restart does the work.

I searched and tried the solutions mentioned by others:

" i accessed the "checks/actions" but none of these applied to when you cannot even get into the scanner. I also accessed "Samsung Members app > Support > Phone diagnostics > Fingerprint scanner." but there was no fingerprint scanner option as it is not functioning... "

but got the same results as @PeteSa said.

when I go to the Settings > Security and privacy > Biometrics > Fingerprints, it says "Fingerprint sensor not working. if this keeps happening, restart your phone."

doesn't that mean it's a known bug?
why didn't they fix it?
no new updates and no ways to fix. what should I do?

Is it how samsung treats their customers?