The mobile data network is disconnected after the screen is locked

Enabling the [Turn off mobile data when device is locked] feature will disable the mobile data network, preventing message reminders and download activities.
To disable the feature, please refer to the following steps:
1. Go to the [Settings] app;
2. Tap [Battery];
3. Tap the gear icon in the upper right corner/[Additional features];
4. Tap [Turn off mobile data when device is locked];
5. Select the [Never] option to disable the feature.