Screen time limits on children’s iPhones randomly deleting

This question has been asked in another thread with no resolution. Why are the Screen time limits I am setting for my kids randomly deleting, sometimes they completely disappear and I have to set it all up again. It kind of makes the whole Family Apple ID think redundant. Short of physically removing their phones after the set time, unsure what else to do. All devices are up to date running the latest software. This issue has been reoccurring for some months now. And it appears I aren’t the only one experiencing it. Any ideas? (Aside from rebooting all devices, removing accounts etc, I’ve done it all to no avail).