Screentime is a buggy nightmare right now. What I found is that you have to let the usage stats load completely before changing 1 setting. You can only set 1 setting then you must back all the back out to the main settings page, then go back in and you get to change 1 more setting. This is really fun when you have 30 educational apps that you have in always allow and the list gets wiped clean. Apple absolutely knows about this. There is no way that QA missed this. It works a lot better from a Mac on Ventura. I can set multiple settings without everything getting completely wiped or having to back out for each setting, however there seems to be some kind of app duplication issue from the mac where you may end up with multiple copies of Chrome or another app. Right now my oldest kid has 5 or 6 of the same app allowed listed in her always allowed list.
I've released some terrible code in my day, but this is really something special. Hopefully they will sort it.