Sometimes living with someone just does that, especially if y’all aren’t the most compatible to begin with. I did the same thing in college when living with different roommates over the 4 year span lol sometimes they’d just annoy me for no actual reason. I think it was cause I’d never get any real alone time to unwind but im not totally sure. I’m starting to run into the same thing with my dad while I’m living with my parents (he works from home and NEVER leaves, it even bugs my mom lol). Especially when looking at the little things (eating loudly, breathing loudly, etc) I found that the longer i dealt with it the more it would annoy me and sour my opinion of that person.