The problem is the screw is very difficult to move and adjust tension.
I can snug these nuts together with a couple wrenches, and then wrench one of them to move the desired direction.
It appears that something is going on with the threading. After the screw moves through the frame, the threading on the screw looks different, it is sort of 'flatter'. I could not capture a good photo of this.
My question is, what to do next to fix the problem of the hard-to-adjust screw? I would like to replace the screw itself, at the very least because the hex head is stripped, but also because the threading on the screw could be the problem, or maybe the screw is bent? I just hope it is not the threading on the frame that is causing trouble. Basically, I just need one of the adjuster screws from this: https://www.probikeshop.com/en/gb/kona-cmphcc-derailleur-hanger/84435.html But not the entire hanger assembly. Any ideas where to go to find something? Should I try the hardware store?