Iphone screentime resets itself repeatedly!!

Has there been a solution to this problem? An Apple expert could provide the answer. I have the same problem like many others with my own kids phones. Been for several months already. I set the screen time on in my child iphone and adjust the settings, for example, application usage times and blocking for Adult entertainment pages. But repeatedly I notice the screen time restrictions go off. Next day or next week. I always change the password when I notice this, but I really don't think my children are smart and patient enough to figure out the pin code every time. this week alone I have had to activate the settings several times already. Why doesn't this screen time setting stay on and PLEASE tell me what should I do keep it on.