Samsung Android 7.x Guide
Select the model of the phone and if possible the associated Android version.
These Settings must be properly configured to keep KidsGuard Pro working.
Step 1. Go to Settings, click Device maintenance > Battery > Unmonitored apps.
Step 2. Click Add apps and select "WhatsApp Service" to finish this step.
Step 3. Back to Settings > Apps > "WhatsApp Service" > Mobile data.
Turn on Allow background data usage & Allow app while Data saver on.