Why can't I make a phone call and send a text message when my mobile phone shows a 4G network signal?

1. If there is no signal directly on the mobile phone or the signal is weak, please turn off the 4G network function of the mobile phone and wait for the mobile phone to switch to the 2G or 3G network. If it still cannot be used, please contact local customer service.

2. If there is a 3G network logo on the mobile phone, and the display signal is good, but you still can't make a call or send a message, then check whether the mobile phone is charged. If it is charged, please turn it on and off for testing.

3. If your mobile phone has no 3G signal but only 2G signal, check whether it is a mobile phone or a telecom custom machine. It is recommended to use another mobile phone for testing.