Please perform the following steps:
>Clear the RAM memory of device (Scroll down notification panel > Setting> Device care >Memory> Clean Now).
> Stop the background running app (Tap on the left soft key and close all the running apps).
>Check for the latest device O/S (Scroll down Notification panel >Settings >Software Update >Download updates manually).
> 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.
For rest of the above mentioned issues, Kindly register your concern in Samsung members app(Open Samsung members app>click on “+“icon>send feedback>Error report/ Ask Questions).