Using The Bumlezone makes it so no mobs drop any loot or XP. I've tested mod by mod, identified this one but I have no idea what causes the issue.

Please say Mc version, modloader, and link to modpack you are using. I just recently tested smacking a bunch of zombies the other day with Bumblezone on and gotten loot drops

It's fabric with the issue. Not forge or neoforge where I tested before it seems. Only learned due to someone in discord asking me about this and providing the info I need.

Fixed now