Neither my finger and the phone screen is dirty. Registering fingerprint on this phone is quite hard even without any screen protector. Some of my finger got detected easily while some others not so lucky. Now since i applied a hydrogel screen protector, it's impossible for the sensor to detect any of my finger. This is a basic feature, used not only to unlock the phone but many app also use this feature. Please prioritize this matter in your update. Now i have to use password to login into my banking app.
Same issue, fingerprint sensor refused to register with a glass screen protector. Don't know if a different brand or type would've worked, but i gave up. Even without the screen protector, this sensor is far from consistent.
A different protector helps. At least for me it did. First 2 was disappointment, one glass one hidrogel. The second hidrogel solved it. It is thinner I think, but probably different material too. I wont advertise the brand because the size problems, it could be 2mm wider, also was expensive.
My hydrogel is 0.13mm 😞 Yesterday i've brought my phone to the service center and they keep for repair. They say i'm the first one with this problem (i'm not completely trust that claim thou). I hope my phone will be fixed...