If you have the 'not feeling well' wobble (not bad enough to be a death wobble) in my case it was caused a couple times by my incorrect setup. I have a 36' Class A, Blue Ox tow bar, and Saturn toad. A couple times now, I have inadvertently hooked up the drivers side pin connection from the Blue Ox upside down. Driving along seemed normal for the most part, but then I'd notice a wobble. The wobble would come and go, but was worse on long left turns.
Stopping the rig, and flipping the Blue Ox connector over at the car fixed it.
Any chance you might be doing that?