LMS

I have the premium version of SafeKids and am monitoring two devices. Initially when I installed on their phones everything worked well and the phone blocked per the time schedule I have put in. I have a couple of questions: Does SafeKids use Background Data and therefore Data - both kids have pay as you go mobiles so don’t want it to eat up too much of their credit. Second question - Background data has been disabled on both of their phones - will this prevent the restrictions from working when they are on WIFI? Both phones are Alcatel 3 running Android 8.1.0 Every time I open SafeKids on their phones the app is switched off. I thought it might be an issue with the update and and have uninstalled and reinstalled and restarted once I reinstalled. Seems to be fine on the one phone for the moment but feel like it will revert to turning off the app again - like it did before. Does anyone have any experience of this?