(Cis guy but can offer an answer to this) Hexbear is quite a large instance that was unfederated for a long time. It also has a strong and specific political leaning and a very particular instance culture. The combination of these factors has caused more than a little friction between hexbear and other instances - something I say with no intention to assign blame to hexbear specifically. While I have personally had plenty of what I will politely call strong disagreements with hexbear users I do think that the majority of it is innocent. It's a big instance with a brash culture and strong opinions, so a lot of people's experience with hexbear was "a lot of loud dogpiling anyone that disagreed with them" even though the hexbear users were just earnestly interacting with the fediverse as usual. This resulted in a whole heap of defederations, and pawb.social is apparently among the group that did that