Please perform the following steps:
> If any screen guard/tampered glass/protection film is available then first disable the fingerprint settings and then remove the screen guard.
> Once screen guard is removed now register the fingerprint again and check the issue.
> If problem does not get resolved, run the device in Safe mode and reconfigure the fingerprint.
> If issue still persists, create data backup and reset the device.
> Make sure to use the central fingerprint parts evenly when you register or scan fingerprint, so that all portions of fingerprint, including the center and corners have been fully scanned.
>Check for the latest device O/S (Scroll down Notification panel >Settings >Software Update >Download updates manually).
For further assistance, register your concern in Samsung members application (Open Samsung members app >> click on “+“icon > send feedback >> error report / ask question).
Team Samsung Members