Slide-outs won't retract evenly

First thing i would suspect is dry brittle slide seals. The electric motors i stalled on Many slide rooms are marginal at best. Anything that might hinder smooth movement will cause your problems. Get some cleaner, clean the seals and lube them with slide seal lube, baby powder or dry lube. Same for the gears, rack, and tubes that support the slide rooms. I know you wont get all of them, but do what you can and then try them.