I once got a complaint to HR that I insulted a coworkers masculinity because I said his shoes were cool. The guy then quit the next day and in his exit interview he claimed I repeatedly talked to him like he was a woman. All I can remember is when I was training him I might have called him "hun" or "silly"? I have no idea. I often call people stuff like goober, goof, homie, hun, bud, etc.

HR told me the entire office was laughing about it. I think maybe I accidentally gave the dude a kind of gay panic or something lmao

Yeah I hate it when people go to HR they are not your friend... They gonna resolve the situation one way or another. Kill them with kindness. It might take awhile, but eventually they will give up.

Until you escape just keep your head down by pretending you don't even know who this person is (hope you haven't told HR your suspicions yet... definitely don't).

If this continues, every time you go in hr just feign ignorance, look like feckless workerbee and lie like you did when you interviewed for the position...about how you love working, and you love your team,the company... Yaknow the game. The good news about HR is they aren't there for the complainant either and they just added another mark on their record (unlikely it is the first) as someone who doesn't work well with others.

I won against my useless boss in her petty hr war by doing precisely this.

someone made an HR complaint about me for being on my phone too often and slamming down objects loudly when upset

The "someone" in question:

I bet this "someone" browses r/neoliberal and goons to IDF e-girls, inflation graphs, and farm animals.

I'm going to over a possible counter view, with the caveat that I don't know your specific situation.

I'm not a big guy, in fact, I don't see myself as a guy at all. Certainly I don't think of myself as intimidating in any way. And yet, I've come to learn over the years that when I get upset/angry, people absolutely do find it threatening. It's a hard thing to understand because it doesn't match my self image at all, and it's not something I can control. I feel like, "Who could possibly be intimidated by me?? I'm just a little nonbinary entity!" But for whatever reason, they do, and I'm in the process of learning how to adjust my expectations accordingly.