The phone cannot use the 4G network / does not display the 4G signal:
1. Please confirm whether the following conditions are met:
1) The mobile phone supports 4G network. For some customized mobile phones, only the SIM card of the corresponding operator can use 4G normally.
2) The operator covers the 4G network locally.
3) The SIM card is a 4G card that supports the 4G network (ensure that the 4G service has been activated, please consult the operator for details).
4) The SIM card has opened a 4G data package.
5) Please confirm that the 4G switch is turned on (some mobile customized models do not have a 4G switch, and the system turns on 4G by default).
6) Please enter Settings - Network and Internet - Dual SIM Settings - Network Mode, and set the preferred network mode to 4G/3G/2G (some models do not have this setting item).
7) Please use the standard SIM card provided by the operator, cutting the card or non-standard SIM card may cause the mobile phone to fail to work normally. If you have replaced a new SIM card, please call the operator, refresh your background data, cooperate with the refresh data, restart the phone and try again.
2. If you still cannot use the 4G network after meeting the above conditions, please try:
1) Go to Settings - Network and Internet - Dual SIM Settings - Mobile Network - Access Point Name (APN), and reset the APN to the default setting in the menu options.
2) Re-switch the 4G switch once.
3) Restart the phone.
4) Restore the factory settings after backing up the data.
3. If you still cannot use 4G after the above attempts, please bring the purchase invoice to the after-sales outlet for testing.