Hi, we'd request you follow the below steps:
1. Clear system cache.
2. Try the same under safe mode:
Hold the power button for 5 seconds => When the screen flashes with option => Press & hold power option => You will get an option to restart in safe mode
3. If still you face the issue factory reset your phone after taking a full backup.
Performing hard reset(data backup is necessary)
1. Switch off the device
2. When the device is off, press (also hold) volume down key and then press (also hold) power key.
After the device vibrates, release the power key (keep holding volume down key) to enter recovery mode.
3. Select "wipe data/factory reset" by volume down key (or volume up key), and then press the power key.
4. Select "Yes -- delete all user data" by volume down key (or volume up key), and then press the power key to start reset.
5. After the reset is completed, select the "reboot system now" and press the power key to reboot your device.