I have owned 5 gas Class A's and there will always be that movement when people move/walk inside. It will be less if you make sure all leveling jacks are down on the ground even if the ground is level to start with. Not sure how the "big DP's" are with this issue, but I don't think you can do anything else on the gassers.
2021 Jayco Precept 36A
2018 Jeep Grand Cherokee