I've registered 4 fingerprints so far, and would like to register a 5th, but it's not possible anymore. I don't know if it's a feature or a bug.
When i try to add this 5th fingerprint, i have the "touch and hold the fingerprint sensor" screen, but the icon of the fingerprint (where the sensor is) does not appear. I try to touch the sensor and i don't have any haptic vibration. So basically i can't add the 5th fingerprint. I just have the text and a white screen.
Latest GrapheneOS on Pixel 7.