Screen time shows as fully used hours in which the phone was off.

My kid turns off his iPhone everyday at school, but the hours spent with the phone off are accounted as “100% used” in Screen Time.

It just won’t say which category of apps it was used (probably because none was actually used!)

This prevents me from setting a time limite for “all apps”, which would be very convenient for me to do. Because if I set it, the moment he turns on his phone after school the allowed time is already up. Just see the screenshot below: 8h31min supposed time, 9 minutes actual time.

He has an iPhone 13 mini on iOS 18.1.

Any thoughts?