2021 Coachmen Pursuit

We have a 2020 F53 V8 under the 2021 Coachmen Pursuit with 25k miles on it. A few months ago, I noticed some extra engine noise midway under the rig. When I crawled under to inspect, I found the muffler had shifted aft at least an inch causing the lap joint (between Catalytic Converter and muffler) to spread enough to present a leak. One of the rubber stoppers was up against the frame and all the support hooks had traveled through there rubber holders to near full travel. I loosened up the clamp and had my beefy son pull it back forward, then retighten the clamp. After the first 100 miles it was fine. Then after the second 100 miles, it has slid back again. I will be personally retrofitting with a sleave-type lap joint clamp to keep it from separating completely. I have not had any technicians/agents/dealers look at it. The only failure indication is exhaust noise from the middle of the chassis... and then, if it slides too far, the separation of the exhaust pipe leading to likely catastrophic results when either end impact the road. There are no strike marks from debris or road hazards. I do not know why it shifted other than, it can.