Ok, It turns out that I was playing normally in my world and decided to grab a trident to get a screenshot, but I wanted to duck and the trident was floating without me holding it visually with my hand. (EDIT: As far I know it was "fixed" in 1.13.2 but it comes back again in 1.14) PD: This isn't duplicated, it just comes back in 1.14!

What I expected to happen was...:

Aiming then crouch and the trident still in my hand.

What actually happened was...:

The trident floated above me.

Steps to Reproduce:
1. Grab a trident
2. Press right click (without releasing it yet)
3. Crouch.

Sorry for my bad English