on both 2.4.2 and 2.4.3, mobs don't drop anything except exp. Haven't tested on clean instance but reverting back to 2.4.1 fixes it. Let me know if you need a mod list

Considering it doesn't happen in vanilla Bubbles instance, yes I sure do need it. Would be a great plus if you did a binary search to find which mod breaks it.

Considering it doesn't happen in vanilla Bubbles instance, yes I sure do need it. Would be a great plus if you did a binary search to find which mod breaks it.

After various tests, I have finally confirmed that this problem happen when bubbles is installed together with RLArtifacts

well, with this bubbles fork,
https://www.curseforge.com/minecraft/mc-mods/bubblesex (bubblesEX 1.6.0)
RLArtifacts functions correctly.
https://mclo.gs/RkiMezi (bubblesEX 1.5.9 , bubbles 2.4.3)