My experience matches this. You can move heaven and earth to teach everyone the exact right way to do things, or you can set some overarching guidelines and move people around or re-define their roles until it starts working. In an environment where the work is always changing the first method never ends and quickly descends into chaos if you ever let up.

Almost everyone loves to do work that other people value, but it's hard to predict how they internally calculate what is valued and what isn't.

See if you can learn why this person has this behavior. Perfectionism? Fear of looking bad in front of peers? Unclear goals?

With some creative thinking it may be that those internal motivations are compatible with tasks that need done. If not, a harder to implement solution would be to see if you can frame some higher level goals they can internalize. Particularly with people on the spectrum I've found that they have a hard time seeing the forest, but if you can explain things in a way they can process they will happily adopt those higher level goals into their value system.

Unless that person is driven to get straight A's on their report card, make it clear you value the right stuff is getting done, but try not to turn it into mechanical process.