Says App Advice:
Ever since iOS 9.1 was released on Oct. 21, a number of iPhone and iPad owners have been experiencing problems with Touch ID fingerprint recognition … Owners affected by the issue are reporting unreliable Touch ID fingerprint recognition, slow response times, and sometimes even a complete inability to activate the feature.
Try these steps if you’re affected by the issue.
Reset fingerprint data
Put simply, try removing your existing fingerprint data from the device, and adding your fingerprints afresh, as follows:
- Open the Settings app and scroll down to tap the Touch ID & Passcode button.
- Enter your passcode/passphrase when prompted.
- Slide left on each of the “Finger” entries under the Fingerprints heading, and tap Delete.
- Once there are no fingerprints left, tap the Add a Fingerprint entry and follow the steps as usual. Repeat for your other fingers.
Wipe and restore
This is a somewhat drastic measure but worth a try if the problem is just too much for you.
I’ve already written a very popular article about how to wipe and restore an iPhone/iPad, so please read that particular guide:
Notably, for obviously security reasons the fingerprint data is stored inside the iPhone/iPad’s CPU and ISN’T included in a backup of any kind, so a wipe and restore effectively means you’re resetting the fingerprint sensing component of the device.
If you find a better cure for this problem be sure to let us all know in the comments below, although if nothing else works then you can always try our NSFW technique… (Seriously, that link is NSFW – save it until you get home from work.)