Huawei applies a default restriction policy for background processes. This prevents Health Sync from processing the sync in the background. You can fix this as follows:
- Open your phone settings menu
- Open the Battery menu
- Make sure that “Performance mode”, “Power saving mode” and “Ultra power saving mode” are all three disabled
- Then select the App Launch menu
- You get a list of all your apps. Search for Health Sync and select the button: set it to “manage manually” and accept all three background options.