> after about the fourth interaction, something about me registers as "off" to other people and they start to distance themselves from me. I have never understood why
I’m not sure it would be helpful, but have you tried asking anyone?
Speaking strictly for myself, it's because I did eye contact wrong.
As a teenager, with standard-issue high-function ASD eye-contact aversion: fake it, by looking only at the bridges of people's noses.
After learning, from doing theatre, that vulnerability is amazing, actually, and eye-contact is powerful: try for it, by looking fixidly at one of their eyes.
After being told by a kind friend, in my early twenties, that I had a "staring problem": shift focus between both of their eyes.
Soon after: figure out that you're supposed to look away from their eyes sometimes.
Since: try to pick up and match their gaze-rhythm. I still have difficulty doing this with some people: there are folks who don't seem to have a rhythm. I don't get them!
My wife told me a few weeks ago that when we first got together (over a decade ago) that the times I forgot to mask - during sex, specifically - sufficiently weirded her out that it's why she broke up with me (for about twenty minutes, lol; she reconsidered on her own). Now, bless her, she says she likes it when I "stare", because she says she knows it means I'm comfortable with her and feeling relaxed.
I've got other peculiarities - and some I haven't noticed yet, I'm sure! - but that's a big one, and how I've dealt with it. I hope that helps someone.
I’m not sure it would be helpful, but have you tried asking anyone?