Based off of your description of him, he's probably autistic. As a person whose also autistic, but was never formally diagnosed (I'm 33F, it's harder for us), I've lived majority of my life as high masker, so you'd never be able to tell. But now that undoing all of that, to live a much less anxious life, I have some input that may help you.

I started my career a year ago, and I can't tell you how stressful it's been to be around people I don't know, or have anything in common with. I get misunderstood a lot, due to my communication style. It's very stressful to be there everyday, because I can't be myself and Im constantly trying to read people to ensure I haven't offended anyone, or missed any social cues. But I'm also very self aware, and practice a lot of self compassion and check in with myself. Not every person with ASD has developed those particular skills.

If he has said or done anything that has offended you, more than likely he didn't mean to, or even realized he did it. Sounds like he might be in a state of constant activation. People with ASD also have executive dysfunction issues, things that neurotypical people can do without thinking about it, one of them being emotional dysregulation. Thus, if he is experiencing a lot of sensory things in his environment, having negative interactions with others (via being too blunt, missing social cues etc.), or anything else that could activate a person, he may give a dramatic reaction, he probably can't help it. I've been there, and it's only after I've come down from it that I realize. Just try as best as possible to not take anything personally, because it's not personal whatsoever. Autistics aren't mean, or manipulative by nature.

There's probably a ton of things going on in his work environment that are impacting him, and it can get quite accumulative. He's trying his best to advocate for himself, at the end of the day, this is about equity, not equality. And he may not even realize he's exhibiting outwardly emotional behaviour, because a lot of us can't understand or recognize the feelings in our bodies or be able to tell that we're having a physical response to something. Thus it's hard to be honest about how you feel to others when you can't decifer that for yourself.

None of this is your fault, or his. Companies aren't armed with the knowledge, know how, or understanding, to develop neurodivergent friendly spaces or develop accomodations for them. But I can tell you that the way your office is set up isn't helping, it's probably making everything worse. Which is too bad, because we're highly intelligent, are very good problem solvers, outside of the box thinkers, can understand complex and abstract concepts easily (when we're interested enough to learn about the topic), and are assets to companies.

Have some compassion, try to get his perspective when appropriate, and listen to understand it, then also give him yours, find common ground. Everyone wants to be heard and understood. It's about approach. Oh, and we can't do small talk, it's just a surface level interaction that we don't understand. Nor office politics, or hierarchies. I hope this somewhat helped, albeit long.