My findings

So, I found that any non 2D item will cause this. Items like the trident are excluded though, since when you hold it, it shows a 3D model. so it will still cause the issue.

When I captured the clip, I thought it was only items that were enchanted, but that is not true. For example, enchanting either a shield or trident still causes the issue.

How to reproduce:

Just place a block (Preferably solid) into your hotbar while you are in survival. You don't even need to be wearing armour.