I have the same bug since last year. Apple support checked my iPhone and I could reproduce the bug on the remote screen support, however they told me that is looks like a hardware error and need to replace iPhone.(I had iPhone 12 Pro at that time)
That was 2022/Feb. I didn’t exchanged but now I own an iPhone 14 pro. The problem still persists.
The screentime setting keeps resetting, sometimes after 1 hour, sometimes lasts for 3 days etc. Even no one uses the iPhone of my kids beside me, it keeps resetting.
When I wait loading of the screen time data, sometimes the setting comes back, but mostly it doesn’t and I have to set it back again. I am pretty sure it’s something wrong with iCloud server and syncing the screentime data.
So it looks like I’m not just one that has this problem. I am thinking to delete my family group and recreate, however I have to move my kids account to different group before I can destroy my own group, and I have not enough information what will happen to my family’s account as I only have iCloud subscription. Like photos or iCloud data my family are using currently.
Did anyone tried to recreate the family group?