Taken all the steps to prevent sway. Still swaying. Help!

I read most of the replies but could not find out if your truck has air leveling suspension or air bags. Air bags and air leveling suspension can cause this issue. The air bags take up the weight instead of letting the weight distribution hitch move some to the trailer and some to the front wheels. My previous truck had air bags which I could not use because it would make the rig very susceptible to wind.