Like Old Bisuit said---get some real weights before you go tinkering with the hitch. You want front and rear axles of the truck, separately, with & without WD hitch, and then add each axle of the trailer separately, with and without hitch.
But in your shoes, I would first 1) check that the trailer is level or has tongue slightly down 2) move some weight to the front of the trailer. You might be a little tongue light. Depending on tank location, some water in the fresh tank could do the trick.
Also check the tire pressures on both truck & trailer.
With that combo properly set up, you should not even know the trailer is back there most of the time.
Single empty-nester in Middle TN, sometimes with a friend or grandchild on board