I'm assistant instructor at my HEMA club, but I'm also a woman and one of the youngest fighters we have. After our main instructor I also have the most longsword experience (except for one or two guys who show up very rarely). While I normally just help out with teaching alongside the main instructor, I've also had to sub in for him a few times.
If I had a euro for every time one of the guys tried to talk over me while I was holding class, I'd have a lot of euros.
I've also seen a woman from an other team blatantly ignoring the women on my team when she wanted to sparr with us. That pissed me off so much.