Perform the following to troubleshoot:

• If your phone/tablet is running HarmonyOS/EMUI 9.X/Magic UI 2.X or later, go to Settings > Battery > More battery settings and enable Stay connected when device sleeps.
  

  Due to the specified design of some phones/tablets, this switch will be grayed out when no SIM card is inserted.

If your phone/tablet is running EMUI 8.X or earlier:

When mobile data is being used:

Swipe down from the status bar on your phone/tablet, touch and hold the Mobile data icon to access the Mobile network settings screen (for EMUI 8.X, go on to touch More), and enable Mobile data always on.

When a Wi-Fi network is being used:

Swipe down from the status bar on your phone/tablet, touch and hold the Wi-Fi icon to access the Wi-Fi settings screen, and go to Configure > Keep Wi-Fi on during sleep > Always.

• Go to Settings > Mobile network > Data usage, and disable Smart Data Saver.
• Go to Settings > Battery, and disable Power Saving mode.

If the issue persists

If the issue persists, contact the Huawei customer service hotline or back up your data and take your device and proof of purchase to an authorized Huawei Customer Service Center for assistance.