A while back, I got my mother (59 years old) an iPhone 8+ to replace an older phone that is now unusable even by her basic standards. While she loves the bigger screen, she has had issues with Touch ID on it. She said that after extended cooking, cleaning or bath sessions - or anything that would expose her hands to some kind of liquid for a while, her fingerprints couldn’t be read by her phone. I’ve witnessed her having these issues firsthand, and even when I had her put the phone on a flat surface and place her thumb on it, the iPhone wouldn’t register it. During the initial setup process, I registered one of my thumbs as well, and I had no issues unlocking her phone. I taught her how to delete and register new prints, but that was a temporary solution - a couple days later, it’s back to square one. We took her phone to the Apple store and got it diagnosed, which showed that everything was working as intended. Is this an isolated case? Or is Touch ID just that sensitive?