According to the Minecraft Wiki, wandering traders can close and open wooden doors, not iron doors. However, they can open them like they're made of wood. It surprises me that a mob can actually open the most unopenable door in the game. How can this be?

Steps to Reproduce

1. Build a small house with an Iron door and a fenced area. 
2. Set time to Day
3. Spawn a Wandering Trader
4. Set time to Night
5. Spawn a zombie type of mob or illager in the area.
6. The Wandering Trader will use its Invisibility potion

What I expected: It will stay over that area since it can't open the Iron Door.

What actually happened: It managed to open the Iron door and go inside the house.

https://youtu.be/Z8HP-4gx87M