Just going to second this point of not really knowing what’s going on in someone’s head: I’ve known a few of people over the years who just had a “weird” (to me) affect, or manner, and it’s only after spending more time when them that I learned to read them properly.
And just speaking of myself, I know I can come off as angry when I’m just quietly thinking, or sarcastic when I’m really just trying to be earnest and straightforward. Like really really trying lol
Could also be that you’ve simply encountered yourself a jerk, in which case, you can safely dismiss them