Despite these communities existing, Boost doesn't load them directly. I can still see posts from them in Local view, but viewing the community directly doesn't work. This happens on multiple different instances.
The (SFW) community in the image is: !announcements@burggit.moe
burggit.moe/c/announcements
(I'm not sure which link style works, so I'm including both)
I also have this problem, exclusively with things on burggit.moe.