Some Samsung Galaxy S10 and Note 10 users have reported that their fingerprint sensor on the device is as secure as they want it to be. It was later discovered that the issue was with the type of screen protectors that the user chooses to fit on.
Samsung explain that the ultrasonic fingerprint sensors have an issue reading 3D patterns in the silicone screen protecting cases and thus unlocking the device even when the fingerprint is incorrect.
They have since announce that they will be releasing a new patch to fix up the issue next week but before that happens, Samsung is advising their customers to not use such covers for now and that they should remove the cover and also delete any fingerprint save previously and register new prints with the covers off.
If you have not tested your device, you should try scanning a non-registered fingerprint and see if it unlock.