Have you considered you are just observing this:
Hexbear is for communists to talk to communists. They get plenty of the "default" liberal opinions from waves hands around vaguely and are entitled to their own community, no?.
Obviously if you go into Hexbear and just start posting anti-China stuff they're going to ban you. It's not like the English-speaking world is bereft of anti-China news articles.
Yeah, I do remember that. That's why I'm not signed up there. They weren't changing anyone's minds with their shitstirring and were doing it for their own enjoyment (which is damaging to all communities, even nonpolitical ones, if people avoid your platform due to trolling).
That said, it was a past problem, and posters on lemmy.world are still out there complaining about Hexbear like they're relevant. I'm speaking about the current situation.
I'm not advocating for them to re-federate with lemmy.world (I have no dog in the race, anyway, being a part of neither instance) but I do remember watching the Hexbear mods/admins shutting down the actual brigading of threads before lemmy.world de-federated. Not sure it was a solvable problem, anyway, Hexbear is rather antagonistic in ways I don't agree with.