Hi. I received my S10 Plus last week. Like for many others, the new FP scanner is very poor in comparison to the excellent one on the S9 Plus
I've registered and re-registered multiple prints of the same thumb and finger . Still fails to recognise them. The only way it does work is for me to briefly lick my thumb, which is pretty gross when out and about I'm pretty sure if I swapped handsets (under 30 days) the new one will be just the same .
Truth be told is that I always struggled with my thumbs on the S6 and S7 Edge; too much wear and tear from lifting weights I suspect. Unlocking from the lock screen isn't a problem as I can facial recognition but it's more an issue with Samsung Pay and access to my Internet banking. I can use PINS, passwords etc but just not as convenient
So, keeping digits moist appears to be the trick...