What we did to cause a bug:

Found outpost and spawning block on top floor, sectioned off the top part with cubes to make it dark... At first they spawned readily for our farm and all seemed well, but after a while the spawns became more and more limited until we are not getting anything now... Checked all caves with xray beneath the ground and lit them all up... Checked again to see nothing spawning at all... Removed all we built on the top floor to see still nothing spawn still...

I have no clue what we are doing wrong and it seems to be a bug... Have seen other people on this forum talk about less spawns of captains but I am seeing 0 at all... Sorry if its just my idiocy but I seriously cannot get anything to spawn on the top of the raid towers anymore and would desperately appreciate any help or anything to fix this