New response from Support:
Cause of the issue:
1. The phone hasnāt given permission for the app to use the data network.
2. App error.
3. phone (2) system error.
Solutions:
1. Check that the app network permissions are opened.
2. Uninstall and reinstall the app.
3. Restart the phone or restore system settings.
4. Test whether other phones can use it normally. If it doesnāt, it is recommended that you contact the appās support page.
And this:
What do I do if I cannot use the 5G network to access the Internet?
At present, some areas may not support 5G network. It is recommended that you ask your friends or call the network operator to confirm whether your location supports 5G network and whether your SIM card supports 5G network.
If both the local network and the SIM card support 5G network, you can try the following methods to fix it:
1. Enter Settings->Network& internet->SIMs to check whether the network setting option of the SIM card selected in data preference is correct:
1) Settings->Network& internet->SIMs, select the corresponding network card, check whether the Mobile Data switch is turned on;
2) Settings->Network& internet->SIMs, select the corresponding network card, check whether the Preferred network type is set to 5G;
3) Consult your network operator whether to enable roaming restrictions. If there are roaming restrictions, enter Settings->Network& internet->SIMs, select the corresponding network card, and check whether the Roaming switch is turned on;
4) Settings->Network & internet->SIMs, select the corresponding network card, check whether the Data warning and limit exceeds the limit
5) Whether Settings->Battery->Battery Saver is enabled, check again after closing
6) Switch on and off the airplane mode or restart the phone and check again
