@oreosimmer01Are you on Xbox or PS4? Is the cheat window opening when you press and hold all four shoulder buttons on your controller?
If you are you trying to use the cas.fulleditmode cheat while you are already in CAS I'm not sure it will work. I think you have to enter the cheats first and then go into CAS. In Live Mode, open a cheat window and try using testingcheats true, then enter the cas.fulleditmode cheat, and then go into CAS. Hopefully it works then.