-Your school should have reported this (you quitted the school) to SEVIC/USCIS after you left the school, not you. So this is your school's fault, not yours and you have no responsibilities for this mistake. So, do not worry about that.
I don't think there is out of status problem because before filing 485 still in good status and anyone got EAD under filing 485 is allowed to work, right?
-I agree with you. Your status is AOS and have the right to work using valid EAD.