Been there done that. I must have some kinda mannish musk, aura or something. I've been called a boy by little kids, even when I had long hair. At my old job tons of people would say 'excuse me sir' etc. I didn't mind, I'm quite androgynous and I find it amusing.
Most times "misgendering" is just an honest mistake or in the scenario of talking to a trans person, its honestly just habit. Especially if you've known them forever. Hell, people with similar names fucks me up enough. I could know you for 5 years and still say a different name if its similar to another close friend's.
People need to lower their expectations of others. If they do get misgendered, feel as if it was gonna happen regardless. People just wanna do enough to get by. When they do succeed in saying the proper things, its a pleasant surprise. I'm not saying to have no faith in your fellow man, just less.