Mine did that. I dont think mine is same model or even brand, but same thing, big bars hanging from chains.
There was nothing out of level or mis-adjusted, but the tension was always different, even if I switched sides...
There seemed no issues while towing.
My solution was to get a
single chain link, the kind that open with a nut and threads that typically is used to attach the safety chain to the receiver, and to bypass one link on the WDH and use this longer (1.5 times the size of the WDH bar's chain link) by using this bigger link.
The effect is that I lengthened that side chain string by a half of a link. This evened out the tension,
I did it in the middle of the chain, but I think better, if room, to put the threaded link on the WDH mount and attach the bar's chain to that.
This is the link type I used
https://www.carid.com/curt/zinc-coated-safety-chain-quick-link-7-16-threaded-mpn-82931.html