Continuing the discussion from OnePlus 7T Fingerprint Sensor will nicht wie ich:
@Bernd15 Yes, your interpretation is correct—I think tapping lightly helps a little bit. I also ended up scanning my fingers twice to have multiple fingerprints of the same finger, which I think has increased the success rate.
I will say that at night, for whatever reason, my fingerprints are hardly ever recognized. Not sure why that is 
Hope that helps!