This is one of the best explanations of what to do to help prevent caravan sway.
https://www.caravansplus.com.au/guides/how-to-stop-your-caravan-swaying-must-see-video-a-4.html
They don't quite understand it.
This is from Bath University in the UK. A much better demonstration with ball weight maintained correctly.
A combination of speed and high yaw inertia (weight at the ends) makes for instability.
https://www.youtube.com/watch?v=PFzrWHTG5e8
Cheers,
Peter
OKA196, 4x4 'C' Class, DIY, self contained motorhome. 960W of solar, 400Ah of AGMs, 310L water, 280L fuel. https://www.oka4wd.com/forum/members-vehicles-public/569-oka196-xt-motorhome