Touch ID not working during charging?

Hi, phuanho.

Thank you for visiting Apple Support Communities.

I understand that your Touch ID isn't working as expected when charging. If the charging outlet is grounded correctly, please take a look at the troubleshooting information outlined below.

Get help with Touch ID

Sometimes, you'll need to enter your passcode or Apple ID instead of using Touch ID:

• If you've just restarted your device
• If your fingerprint isn't recognized five times in a row
• If you haven't unlocked your device in more than 48 hours

• If you've just enrolled or deleted fingerprints
• If you're trying to open Touch ID & Passcode in the Settings menu
• If Require Password is set to Immediately under Settings > General > Restrictions

If you still need help, follow these steps. Try again after each step:

1. Make sure you have the latest version of iOS.
2. Make sure that your fingers and the Home button are clean and dry.1 For the Home button, use a clean, lint-free cloth to wipe off any dirt or debris.
3. Your finger should cover the Home button completely, touching the surrounding metal ring. While Touch ID is scanning, you shouldn't press down hard, tap too quickly, or move your finger around.
4. If you're using a case or screen protector, make sure it doesn't cover the Home button or the surrounding ring.
5. Tap Settings > Touch ID & Passcode. Make sure that iPhone Unlock or iTunes & App Store is on, and that you've enrolled one or more fingerprints.
6. Try enrolling a different finger.
7. If you can't enroll any of your fingers, take your device to an Apple Retail Store or Apple Authorized Service Provider, or contact Apple Support.

Use Touch ID on iPhone and iPad

Cheers

This is an easy fix. With many cases the problem is in grounding the phone when charging, you will see that the phone will work normally case-less while charging, but a quick fix to this issue is to put aluminum foil preferably double stacked between your case and the bottom of the iPhone, this will allow your phone to be grounded while charging on an iPad charger.