My last phone was in a very hard plastic sturdy case, to stand dropping when riding motorbike, but the fingerprint sensor on the back was in a 3 mm deep pit, it was no problem to touch it without thinking about touching the sensor. How can you use the phone on a surface? Even with face unlock, i barely can do anything with it if its not in my hand. You can hold and use the phone reliably, only by touching its back, so the fingerprint sensor if there is. I touch different parts of the screen, not that single point where the sensor is, also i need to hold itt differently, to make that crappy in screen sensor work. If it works at all, as since a month it barely does, sometimes it even disappears from the menus too. One of my friends just replaced his samsung s20 too as the fingerprint sensor was barely working, just as my huawei's sensor. I also see many fingerprint sensor problem topics across the net, all phones mentioned have in screen sensors.