I have exactly the same problem. My hair is cut in a mohawk, sides shaved right down to the skin, I wear black pants, biker boots, a binder and guys shirts, I even wear a pair of big goggles around my neck (it's a steampunk thing) and I still don't pass. Not a damn chance.
I don't act feminine at all, but still everyone just instantly sees me as a girl. I don't get come onto though, so I suppose that's a good thing. Even though I like guys, being hit on by a guy because he thinks I'm a girl makes my dysphoria skyrocket. However, because I dress and act masculine, I get insulted a lot by people calling me a lesbian, butch dyke, etc etc.
There's nothing more I can possibly do to look male. My voice, body, and face just give me away instantly.
It's very depressing 🙁