why do I make him so uncomfortable?? shy guys help!!!

me and this guy go to the same community college and I'm pretty sure we're in the same major as we've had a few specific classes together before. I don't remember ever talking to him, though its possible I have and don't remember. now we have one class together and he acts so deeply uncomfortable around me and I don't understand why.
for the first few months of this semester I would sit in the same seat every day and this guy would sit near me (same row, but with an empty desk between us). I noticed he would act very awkward around me and I'd just try not to look at him to not make him more anxious.
one day we arrived to class at the same time and his reaction was, like, upset? instead of just holding the door open for me, he kinda flung it open. and when the sign in sheet was being passed around, he flung it onto the empty desk between us instead. I got upset because I found that rude, but I didn't say anything. instead, I changed seats a week afterwards to the back corner of the classroom. well, fast forward to today and I changed seats again because I have trouble seeing that far away. I ended up sitting in the seat that was to the back left of his usual seat and his reaction when he came into class was just pure discomfort / anxiety / maybe even anger?? I'll list the things he did so this doesn't get way too long:
-almost sat in the seat in front of his usual seat, changed his mind and walked backwards to his seat
-put his head down after sitting down
-angled himself away from me during the beginning of class
-kept leaning away / hunching over away from me when I'd move (like when I crossed my legs or took my glasses off to clean them)
- won't speak when I sit near him, but would answer the professor's questions when I sat away
-just generally very visibly uncomfortable with my presence and looks almost angry
(towards the second half of class he acted a lot less nervous and also this all happened in my field of view as I was looking ahead and attempting to pay attention to the lecture)
Let me reiterate that I don't remember ever speaking to him. we've seen each other around campus a couple times and I really don't think I've stared at him (though I guess it's possible??). I'm anxious too so I understand being anxious, but why do I make him so visibly uncomfortable?
one last thing: usually when class is over either he will leave way before me or wait till after I leave (I'm assuming so we don't leave at the same time?). today he got up when I got up to leave and, despite me taking a bit to gather my things, he ended up directly in front of me when leaving. he didn't say anything, but didn't bolt away like I expected him to based off his behavior in the beginning of class.
after that, I saw him go towards the bathrooms, so I went to the ones a floor below to give him space (I really do not want it to seem like I'm following him). afterwards, I left the building and sat a little bit in front of it so I could get my headphones out of my purse. I heard someone leave the building and didn't think anything of it, but then I glanced up and it was him. except this time it almost looked like I nearly caught him looking at me, like he got super rigid as he was waking by.
I don't understand why my presence causes such an adverse reaction or why he wouldn't just fully avoid me if being near me is so bothersome. can anyone pleeease tell me why he might be acting this way??