For autosync (including instant upload) to work apps must run in the background. If manual sync works but autosync does not, your device probably is kiling background apps. On devices from Huawei you need to modify some system settings.
- Battery optimization: this is the so called “doze mode” which prevents certain tasks from running if your phone has been sitting idle for a while. Furthermore apps which users do not open for some days are considered unused and are suspended. This is certainly not good for background sync apps. You need to turn off doze mode. There is a section in the system settings Apps > Settings > Special access > Ignore battery optimization. Switch to “All apps”, find our apps there and change their battery optimization setting to “Allow” (means allow to ignore battery optimization).
- Close apps after screen lock: this option is under Battery in the system settings. If it’s enabled (the default), apps are killed whenever the screen is turned off. This option must be turned off for our sync apps.
- Close power-intensive apps: also under Battery section in the system settings. When sync is running in the background to upload or download changed files, the system considers the sync app as power-intensive. It prompts a warning and kills the app. This option should be turned off, definitely the killing part and perhaps also the prompt. Most of the time they get it wrong, the warning is annoying. This is true for most of background apps, not just our sync apps.
Huawei keeps moving those settings around and even changes their names from one system update to another. If you can’t find the above mentioned settings with the exact same names, try to look for something similar in the device settings.
Huawei devices also tend to suspend running background services when the device is not being charged and used. Autosync may seem to take very long, even hours. This is only because apps are suspended in the middle of sync operations. It’s annoying but by itself is not a cause for concerns.