Jeff, can you give a little more info? I think there are 3 different pins offered. A standard solid, the one that rocks (sort of like the MorRyde), and the third is the Tri-Glide.
Is the pin it's self actually moving or the plate above the pin? The pin it's self should be gripped by the hitch jaws and should have very little if any movement, but depending on the attachment method there can be movement of the rest of the pin box. We have the Tri-Glide and the pin doesn't move but the rest of the box and front of the trailer move back and forth and up and down, which is exactly what it's suppose to do with the Tri-Glide.
If the pin is actually moving, I would make sure the jaws are closing properly to grip it and if that's ok I would look at the hitch mounting bolts. A couple over on the MOC Forum found the bolts missing on the rear mounting rail allowing their hitch to lift up on the rear two or three inches, not good.
Let us know what you find.
Michelle & Ann
2018 Chevy 3500HD Crew Cab High Country DRW, D/A, 2016 RW39MB, Dual ACs, Auto Level, Auto Sat Dish, Stack W/D, King Sleep #, 17.5" Sailuns w/Disc, MORryde IS & Pin, Comfort Ride Hitch, 5.5 Onan, Res Fridge & Induction Cook Top