Take a look at Blue Ox website:
Blue Ox Sway Pro
You can see in the images the difference between "standard" and "underslung". Note they put "Undrs" in the part numbers for that type of coupler. "Underslung" being the coupler mounted to the bottom of the trailer frame, and "standard" being the coupler mounted to the top.
The difference is the angle of the head and the arms (which unlike several other setups like the E2 and the Equal-i-zer, is NOT adjustable). This makes sense if you think about where the arms have to go to the cam chains in relation to where the hitch ball has to go to get into the coupler.
If you have an "undrs" hitch head, and have an "overslung" coupler, (or vice versa), you're going to have problems just like what OP is having, like binding and difficulty with proper adjustment.
I had to do quite a bit of research to figure all this out back in the day, and there's NO WAY I would trust any dealership to know or care about the difference. Not only are they trying to set up a WDH on an empty trailer (which is
at best a good guess), but I've heard of tragically few that know how to do it right in the first place. Not only do you have specific setup instructions for different hitch types, but trucks have different specs too.
All of that said, OP's does look better with the bar inverted. Gotta verify the correct hitch for the coupler, and go get some weights to see how close they got to "correct".
ETA: Pro-tip on the Sway Pro; go down to Harbor Freight and get a breaker bar and appropriate sized socket for the cams. Mine came with a flat bar for the cams, and it was **** on my hands...