2002 Ranger 2WD Regular cab XL or XLT would have 9" brakes/Drums.
4x4, extra-cab, tow-package would get 10", I think Edge and Sports packs also.
If you had 10" drums you should have noticed because backing plate would have looked way to large for the shoes.
Self-adjusters should only work when backing up and using the brakes, or when emergency brake is used.
Either of these cause the adjuster lever to push on the "star" wheel in the direction that UNscrews it, so it pushes the shoes apart farther at the bottom.
If the star wheel was installed in reverse or threads were reversed then each time you used the brakes going forward, the shoes would get tighter and tighter.
The star wheel threads are different on each side, one is regular "lefty loosy, righty tighty", the other is reverse, "righty loosy, lefty tighty", lol.
If you got all new parts maybe they gave you two with the same threads