Time limits do not work correctly on child’s ipad

I set up a simple 1 hour 15 minute time limit on my kids iPad (a change from a previous, more complicated set up). I have two issues:

1. The settings continue to revert back to the old settings. I’ve tried changing it on both my phone and the actual iPad, but after a day, they revert back
2. Today my son’s iPad locked all the apps prior to the 1 hr and 15 minutes being up. It looks like it double counted two apps- the total for two different apps was greater than the maximum time, but the total time on the iPad was less. Is that possible?