Gloss Paint

The wall should of been prepped with a coat of what before the semi gloss paint was painted on the wall?

I am having the same exact problem and our bathroom wall was just recently painted. Before it was painted it had semi gloss paint and it got repainted with semi-gloss paint and well my daughter started peeling it somehow. None of the other rooms that were painted are having this problem. So I need to know what goes on the wall before the white semi-gloss paint to make sure it doesn’t peel?

A primer coat of paint.

Painting MDF Subwoofer Boxes w/ Gloss Paint & DaveTheBoxGuy Car Audio Designs – EXO’s BIG BASS Wall