That was very annoying for me too while i was using stock android for a while. There are ways to raise the amount of attempts as i read, only i never tried. But Sailfishs inability to wake the device from FP-Reader fixes this behaviour On sfos you have to first wake via power button and then just roll down your thumb to nicely hit the reader below the button while in Portrait. Works very reliable now for me. With other fingers it is less convenient since you usually want to unlock while in a car mount or such. So you do not see the FP reader but need to move from the PW-button to it blindly which sometimes take a while to master. The placement seems to be a feature tho since it is most convenient to unlock when you wake the phone by opening the KBD to landscape and then use the index finger, which in my case is exactly long enough to hit the FP-reader behind the angled screen comfortably and exact while the hands are in regular "holding" position! But since i did not send finger length data to F(x)tec at any point it might be coincidence