People always pretend that's a tumblr thing, but if it ever was it has long spread beyond that and it's now a community wide thing that i have seen play out irl more than once. And that shouldn't surprise anybody. When you teach men to act this way, some will always take the bait. It's how patriarchy sustains itself, by offering men safe options to hurt women. Most men only do this in subtle ways they may not even be aware of, but the number of those that are more brutal is always large enough to cause a problem and the number of those who flat-out refuse to hurt, exploit or sideline women is way too often too low.

So how do you deal with this without excluding nonproblematic trans men from your space? Obviously making it "non-men only" cannot be the solution. While it can make sense to have some events restricted to certain queer identities if you have the capacities, just so they have a safer space for themselves, we cannot organize community in a way that shows all cis gay and cis bi and trans men the door. These are still marginalized queer identities that have aligned class interests with us, and besides that nobody wants a door policy that determines if somebody is too masc to enter.

It's important to not make this about these men's gender identity, but about their behavior. Their behavior is openly (trans)misogynist, exclusionary and ultimately aimed to take your space over by bullying trans women out of it. People who behave in that way need to be barred from your space. It's an unfortunate reality of safer spaces under patriarchy that they need to blacklist some people, and these guys sound like prime candidates for that. You need to purge them.