christiee Are you using a screen protector? If so, enable the setting called "Increase touch sensitivity" in Settings > Display > Scroll to the bottom. Does that improve things?
If not, you could be using a screen protector with poor touch support.
I've never had issues with Spigen protectors.
You could try registering the same fingerprint several times. That has slightly improved the fingerprint sensor accuracy in the past for people using screen protectors with poor touch support.