• Steps to reproduce the bug : get a golden pickaxe, find a copper ore and break it with the golden pickaxe.
• What it's expected to happen : you get a piece of raw copper.
• What actually happens when you follow those steps : you get nothing.

NB : in the video, the pickaxe is enchanted with Solidity I. There is a plugin (blockshuffle), but I dont tkink that it can interferate with loots.