The Mob Stacking Plugin?

If you could be a little more descriptive of the bug - when it happens, what triggers it, is it a specific MOB?
"IT BASICALLY GLITCHES OUT TO EVERYWHERE." doesn't help me much.

 

Pigmen on soul sand fall down a block (but not a big issue)
Full stack sometimes die when one is killed
Spiders stacks glitch into walls when killed

 

The same bug causes mobs to fall through hoppers and phase through other non-solid blocks such as iron bars. It's because the stack teleports to the center of the block every time you kill one instead of staying at the same exact coordinates.

 

Yeah I have had my stacks disappear occasionally once attacking them, pretty frustrating

 

This has been a thing for a long time, unfortunately Mario hasn't been able to find what exactly is causing it to fix it.

 

Good news, 2/3 of the above glitches have now been fixed.
- Spiders (and all Mobs with odd hitboxes) won't glitch into walls or through blocks when you kill them.
- When mobs are kills on a half slab, chest, soap sand (any block that isn't full) they will no longer fall down a block.

We are still working to resolve the issue where the stack disappears as this is much more complex.

 

@Eil breeding rabbits and pigs doesnt work neither