Flying cat housekeeper can't switch networks.

According to your description, you can try the following methods:

1) It is suggested to change the network mode: Settings-Connection-More Settings-Mobile Network-Network Operator to re-select the search network.

2) It is recommended to take out the SIM card, wipe the SIM chip with an eraser, and then re-insert the SIM card into the mobile phone.

3) It is recommended to replace other SIM cards as much as possible.

4) If it still exists, it is recommended that you restore the machine to the factory settings and back up important data such as phone book, video and pictures in advance).

5) It is recommended that you try to upgrade the firmware.