Hi, we'd request you follow the below steps:
1. Clear system cache.
2. Please try to enter "Safe Mode". If the function works well in Safe Mode yet the issue remains out of Safe Mode, please check for any disturbance from the installed 3rd party apps.
# How to enter and exit "Safe Mode"https://www.asus.com/support/FAQ/1005163/
3. If still you face the issue factory reset your phone after taking a full backup: https://www.asus.com/support/FAQ/1006346/
4. Last option would be to visit the service center to have a check. Locate here: https://www.asus.com/in/support/Service-Center/India