Your entire post is about managing a neurodivergent person. That’s a diagnosis.

It’s completely inappropriate to make assumptions about a co-worker’s mental faculties, and to act on those assumptions.

OP did try talking to the person but frankly, doesn’t seem very experienced in that regard.

OP needs to build a working relationship with this guy such that he doesn’t respond to feedback as though it’s a personal attack. The only way to do that is talking.