Mine isn’t taught either, just thought that is the way they are. Wonder if I should have mine looked at.
What I happened to notice today,as I have the tight/slack cable issue with tailgate open is..........
On each side of the bed,where the tailgate locks into,is two sheet metal pieces,spot welded in areas etc....from the top of bed to bottom of bed. The side (in my case,the passenger side) that is tight,the piece of spot welded sheet metal,is higher up,in comparison,to the slack/driver side.
I looked very briefly if there was a way for adjustment,via a nut/bolt where the tailgate pivots,and where the cables attach,and saw nothing in a five second glance.
Possibly others can look at theirs,and see if sheet metal end caps are higher/lower from each other. Mine appeared to be an 1/16”-1/8” difference.