I know it sounds bizarre. The fingerprint login success rate started decreasing over the course of 2 days until it wouldn't work at all. Happened even after re-adding the fingerprint multiple times, restarting, waiting it out for 1 full day until it became impossible to fingerprint in at all with the right thumb.

I have a protective screen but it has never given me problems.

Solution: added 2 right thumb finger prints. Works perfect now.

I wasn't deliberate in trying to isolate the issue. Just wanted to get it to work for now. Let this be a data point. If anything, adding two fingerprints for your main login finger MIGHT increase the login success rate if it's failing too much.

    Such2938

    Agreed. It seems the fingerprint readers don't become more accurate over time (as the old iPhone fingerprint readers claimed/seemed to do). It would be nice if Google made them better, but I accept it as a necessary annoyance to have GrapheneOS on my phone.

    I've had to re-enroll my fingerprints many times for whatever reason. I've seen advice to enroll the same fingerprint twice has worked for others as well.

    Such2938 This has been known for some time and was a recommended solution to the sketchy fingerprint reader on the Pixel 6. Increasing the touch sensitivity was another suggestion.