Huawei is using very aggressive battery optimization settings on many of their devices, causing Android apps to doze and quit shortly after the screen goes off. This can cause Safe Lagoon to stop. Here's how to fix it:
1. Configure the Phone Manager app:
Open Phone Manager, go to Cleanup, and tap the Settings icon on the top right of the screen to disable automatic cleanup.
2. Block the Phone Manager app by putting it on a Blacklist to prevent this option from being re-enabled.
3. You will need to configure the battery settings on your device (you can check the EMUI version on your device by going to Settings > About phone):
On your Huawei device, go to Settings > Battery and disable both Power saving mode and Ultra power saving mode. Tap Launch, then find and tap the Safe Lagoon app to disable the Manage automatically setting.
Ensure Auto-launch, Secondary launch, and Run in background are all enabled and click OK.
Go to Settings > Apps > Settings (small gear icon at the bottom of the screen) > Special Access > Usage access > Safe Lagoon and set Allow usage access to ON.
Still in the Battery options, tap the Settings icon on the top right of the screen and ensure the "Power-intensive prompt" and "Close excessively power-intensive apps" settings are disabled.
EMUI 3 and 4
On your Huawei device, go to Settings > All > Device > Power saving > Protected apps > Safe Lagoon and choose Power-intensive.
Go to Settings > All > Device Manager > Startup Manager and add Safe Lagoon.
Finally, go to Settings > Smart Assistance > Notification Panel and and uncheck the Notification settings.
Other Huawei devices:
Open Settings > Device > Power saving > Protected apps > Safe Lagoon and turn it ON.
Open Settings > Device Manager > Startup Manager and add Safe Lagoon.
Disable Ultra Battery mode: Go to Settings > Smart assistance > Notification Panel and uncheck the Notification settings.
Block the Phone Manager app on the Safe Lagoon app blacklist to prevent your child from forcing Safe Lagoon to close.
Note: depending on the device model these options may vary. You can find them using the search field at the top of the Settings screen.