Mobile phones often make phone calls, which often turn into SMS notifications. What's the reason for not answering the phone?

I suggest you check the phone bill first to see if there is any arrears. You can't make calls and answer phones if you owe money. If there is no arrears, it is recommended to make a good data backup and try to restore the factory settings of the mobile phone.

The first possibility is to turn on the blacklist function. Generally, in the Call Center → General Call Settings → More → White List, turn off this function to make normal calls.

The second possibility is to install mobile phone 360, call manager, mobile phone housekeeper and other software. This kind of security software is likely to turn on the blacklist function and anti-harassment settings by default. If it is not the above two situations, it is likely to be a problem with mobile phones and mobile phone cards.