1. Check whether the blacklist is set. You can check it in the harassment interception of the mobile phone housekeeper.
2. Is the mobile phone loaded with 360? If so, uninstall 360 and try again.
3. Go to Settings-Call Settings, select "Use only 2G networks" and try again.
4. Because 4G only supports data services, and call services need mobile 2G or 3G network support. If China Mobile's 4G network is not equipped with 2G cell information, it is impossible to receive incoming calls. In this case, please call 10086 for feedback and ask the operator to solve the network configuration problem.
5. When there is a long pause, pay attention to the signal icon of the mobile phone when you wake up. Check whether the standby device is disconnected.
6. Check whether the mobile phone is in arrears. If it is normal, you can restart and try again.