Yeah so mine has it's moments. This will sound odd but, during the course of the day it's really bad, night and mornings it's really good. Looks like my hands get really dirty in the day or something!Any advise... My Touch ID seems to be significantly less accurate and more hit and miss 7months into ownership. No drops or dings or other funny stuff. Also not an excessive app user so I really only have the main few installed. Any guesses as to why and how to fix?
So no answers for you I'm afraid, but you're not alone. And it has gotten worse the last month or so - never had this issue the first couple months.
Do you perhaps have a screen cover that has shifted slightly? Mine did and it affected how much of my thumb came into contact with the home button.