Hi
@NLMY and warm welcome to the community
👋Do you have any screen protector installed? If so try to remove it.
Try to re register fingerprints.
Try *#0*# in phones dialer (autoblocker needs to be disabled) white screen pops up find sensors tap on it then find fingerprint and press normal scan and check if all pass.
Wipe cache partition on your phone
Power off your device completely.Press and hold the Volume Up and Power buttons simultaneously.Release the buttons when the Samsung logo appears to enter the Recovery menu.Use the Volume buttons to navigate to Wipe cache partition.Press the Power button to select it, then confirm your choice.Select Reboot system now when finished. (You might need to plug your phone to tv, PC etc via USB beforehand)
Try diagnostic tools in members app.
Also try safe mode and see if fingerprint works it might be 3rd party apps who cousing the issues :
https://www.samsung.com/uk/support/mobile-devices/how-to-start-my-galaxy-device-in-safe-mode/
