For somebody to hopefully better help, please, in Settings > System > About the phone:
- Phone model (TA-????)?
- Android version?
- Security update version?
- Your country?
- Your mobile operator / carrier?
Or maybe backup all personal files on the phone, remove the SD memory card (if any), then try a factory 'hard' reset the phone and see how it goes?
Please make sure to insert an active SIM card, and connect the phone to a reliable Wi-FI (if possible) during the first start up after the reset.