Yeah, it worked, but just like u said factory resetting should be the last option.. if it's a system problem causing it not to work then it will work. But if it's the fingerprint sensor that has a fault then it won't.

Alright sure. That once happened to my S20 FE

Don't forget to check for updates as well before u do the factory reset... backup your essentials ✨️

Try resetting it then if that fails take it to a phone technician for fingerprint sensor calibration or if the fingerprint sensor is faulty they will tell you to replace it... Hope this helps you 

Alright