I live near a jungle temple and had hopes to find the bounding box and turn it into a creeper farm of sorts, however, when I went up to test the spawning before altering anything with the temple, I came back down to observe with freecam and there were several zombies and skeletons and like one creeper. I even attempted it again after restarting my game and achieved the same results. Is there any way to fix this? Or am I simply misunderstanding the concept?

Edit: I did check the bounding box, and it doesn't actually go below the temple in the "basement" area. I will test some things and see what happens.

I think you are seeing the effect of gnembon/fabric-carpet#1699