May have fixed the dishwasher with a garage washer
Noticed the lower arm of the dishwasher was in the same spot several washes in a row, so I got suspicious of the gap between that top nut and the arm. It looked like a lot of water could slip past. I found a small washer that fit almost perfectly in a junk box in the garage and now it seems to be working better.
Was that a washer from The Can™? No quick fix is complete without three different screws fished out of The Can™
Of all the hardware I have squirelled away, washers are always the one in short supply.
Because of course it's a dishwasher, this happened
So I bought an assortment of nylon washers then washered my washer again and it seems to be doing well.