Intermittent jerky towing of 5th wheel

I might have added 50-100 lbs of stuff to the second trip but it would have been aft. One issue that concerns me with the turnover ball is that they didn't install any U-bolts in the truck bed. The ONLY thing in the bed is the turnover ball hitch. We are newbies but we did test the truck after engaging the hitch by extending the front jacks to "lift the truck bed" and it did do that. Is there anything else with a turnover ball that we could be missing? The gooseneck attachment is a "Lippert"? placed on the kingpin of the 5th wheel. (if this makes any sense). I am wondering if we should replace the breakaway brake? But, when it popped off it gave that error message on truck console, so I think it's working ok. Mud in tires? That should just give a rough ride till the mud falls out. It just has intermittent jerking, if that sounds like anything to y'all.