Elytra enchanted with mending wont work 

What I expected to happen was...:
Searched a;ll over the internet for a bug report or maybe if the game had changed since the phantom update, found nothing and usually would be able to use mending on my elytra.

What actually happened was...:
Waited a while with over 30 levels of exp and the damage stayed the same with mending enchantment.

Steps to Reproduce:
1. Not necessary