Experience needed: New RV delam bubble on rear wall

I tried not to post the brand but didn’t realize it made a difference. This new TT is a 2018 Coachmen Freedom Express 231RBDS. The rear wall is the aft end of the rig and not a sidewall. The aft wall does not appear to have waves when looking at an angle, only the bubble. The shower is the only item opposite the wall of the bubble. I’d be grateful to know if the aft wall of this coach is not made with the same material as the sidewalls for this brand/model.