The operator may not be displayed for the following reasons:

Check whether the current mobile phone signal is good. If the mobile phone signal is not good, it will display no service.

There may be a problem with the mobile phone system. It is recommended to restart the phone or restore the network settings.

Check whether the mobile phone card is installed. If the mobile phone card is not installed, the operator cannot be displayed.

Check whether the current mobile phone balance is sufficient. This will also happen if the mobile phone balance is insufficient.

It may be related to the local network operator. It is recommended to call the manual customer service number to check.

Check whether the airplane mode is set on the phone. If so, just turn off the airplane mode.