Zombies and Zombie Pigmen do not show holding items

Cannot confirm, sword within first 4 pigmen I came across.

Are you trying to say they should ALL have swords?

Confirmed, pigmen spawn with swords, but do not equip them.

Could this possibly relate to my problem? My problem is that I use /summon to spawn a zombie with CanPickUpLoot set to 1. It doesn't take anything I give it. I then use an NBT editor and see that it's set to 0. I change it to 1 and reload Minecraft. The zombie still doesn't pick up anything I give it.

Added a picture

I found they will still drop loot you give to them. They won't equip it, though

Do they use the sword when attacking you? Or do they do 1/2 heart of damage?

Confirmed, looks like it is a render bug in the game, because they deal more damage than 1/2 hearts.