If you are familiar with the term tankie, hexbear is the china-fan tankie instance and lemmygrad is for those lusting after Stalin and the soviet union.
Lemmy.ml is a bit more low key about it, but equally authoritarian communist when it comes down to it, as evidenced by the op.
Especially the hexbear users have an extremely argumentative instance culture and will even brigade comment sections critical of the great leader, so most users and even instances block them outright.