The walls were contaminated, and the primer was not a sufficient blocker to that contamination. This is why every good paint job starts with washing the walls as the first step. It may not prevent crackle or bleedthrough on some contamination, but it reduces the chance of issues.

You need to get a palm sander, seal off the room with plastic, Exhaust the air out a window, supply a filtered hole in your plastic with some cheap hvac filters, wear a respirator, and go to town sanding all of thr pant off of the walls. You need butter smooth.

Then you need to paint with a stinky alcohol based shellac primer, like BIN. That will seal anything in that survived the sanding. Do 2 primer coats, and lightly sand with a high grit, to achieved ultimate smoothness. BIN powders up well, and will create a smooth as glass surface, if you have your sanding and painting skills on point.

After your first finish coat, use an angled glancing light to look for issues of crackle or alligatoring. You may need a can of BIN, to spot prime any stubborn areas. Do wait for full dry time between primer and top coat. If you top coat too soon, you are trapping vapors under that coat, and it also can cause some wrinklng. Also pay attention to recoat times for the topcoat, for wet on wet spray application, vs wet on dry application.

Look on the primer can, and read it well. Make sure it says, sealing bonding primer. That will seal, your walls, and provide adhesion for the new coat of paint.