Looks like a WDH without integrated sway control, but maybe using 1 friction bar ?? Also, the rear of the truck seems a bit low.
With a 33' trailer, a 2nd friction sway control bar might help. a WDH with integrated sway control might have been a better choice, but maybe work with what you got and see if the 2nd friction sway control bar helps.
Depending on what the WDH manufacture suggests, a bit more weight distributing may be in order. That involves tilting the head back 1 more notch, or using 1 less chain length if you are not using less chain lengths than what the WDH manufacturer suggest. Doing fender measurements or doing 3 weigh-ins at a CAT scale will give you an idea of what is going on.
The scale weigh-ins involve 1 with the truck and trailer with the WDH spring bars in place, 1 with truck and trailer without spring bars, and 1 with just the truck. Weight with each set of tires (the trailer tandems being 1 set) on a separate platform. Keep all passengers and cargo in the same position each weigh-in, as well as the same fuel level...........in other words, do all 3 within the same trip.
Doing the CAT scale thing will also give you the percent tongue weight vs. trailer weight, which if too light could contribute to sway.
Chap , DW Joy, and Fur Baby Sango
2006 Ford F150 Super Cab 4x4
2008 Surveyor 263