Steps to Reproduce (there's multiple ways, here's my way):
1. do the /give command to give yourself armor with the Unbreakable tag {Unbreakable:1}
2. Use an anvil to enchant the Curse of Binding Book on it
3. Now you can wear it and it can't come off unless you die if /gamerule keepinventory is false meaning you can have to lose valuable armor as a result of this.
Since it's got the unbreakable tag you aren't able to get rid of the armor by letting the durability wear off which was how it was intended in the first place. It acts basically like Curse of Vanishing but with Armor which was definitely not intentional.
The proof I have shows me getting hit by a spider with the armor on and it shows that the durability doesn't drop thus not being able to take off armor that way.
MC-107636
Armor with Curse of Binding doesn't come off if Armor is unbreakable
Resolved
Works As Intended
0
I have a feeling that this is intended behavior. What else did you expect should happen? It's curse of binding. It's what it does. Map makers may include this in their maps, if they do, they have the right to do so and you have the right to not play their maps. Also, survival does not offer a way to get anything with the unbreakable tag. Meaning that for what ever reason, you decided to go into creative, add binding and unbreaking and put it on. I'm sorry, but this is really a non issue.