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

Add another sway bar, I had a friend who had camped for 50 years, he always had 2 and when he would get on the interstate he would stop and crank them both down, and when exiting the interstate he would stop and back them off.

He said he never had a sway problem, I never had a TT that I felt the need for this but I can see where it would help on a sway prone TT.