So zombiess and drowneds can now pick up items. If they pick up sword or a piece of armor, it is all good and renders as it should.

But if they pick up anything else (eg. axe - I used it in the video listed below) it goes into their inventory and obviously cannot be picked up by the player anymore. Even after the axe is seemingly in  the inventory of said mob, it doesn't render, nor inflicts additional damage like swords do. And when you kill the mob it doesn't even drop even though pickuped armor pieces drop like they should. The axe just popped out of existence like it never existed.

Video shoving the bug:

https://youtu.be/nZxwXd37pS8