iPhone app time limit kicking in too soon

[aperolspritzbasicbitch]

Hi
Our year 6 was gifted a phone for Christmas - iPhone 13.
I've set up downtime etc so that the phone can't be used after a certain time, but I also wanted a time restriction on apps.
Originally I set this for 4 hours (obviously not wanting her to have that amount of time usage a day, but new tech, school holidays - figured I'd be lenient to start with)
Supposedly this timer refreshes at midnight, however the time limit is kicking in super quickly, this morning it had kicked in by 9am, she had barely used it - the phone downtime only ended at 7!
Any ideas where I'm going wrong?

Could it be background activity? My battery life was being eaten by this (new-to-me iPhone 13 mini). Not the same but worth a try!

In settings - App store, scroll down and turn off In-app content. This stops apps running 'in the background'. I have auto downloads and updates turned off too.