Self adjusters keep overtighten

Looks like the park cable is out of adjustment. Holding on partially causing the brake to be held on partially. It will react the way you describe.
That is something to investigate. If someone has been under the car and drawed up the park brake cable adjustment, All new hardware kits both sides wouldn't cure it.
There's another recent thread about altering front spring hangers or whatever it takes to move the rear axle back an inch or so. Probably 8.25 replacing 7.25. Anyway... In those cases,, or where the park brake cable has been rerouted for subframe connectors, Readjusting the cables might be necessary to avoid this type of brake problem.