Zombies Won't Break Birch Doors

Process:

1. Create birch door
2. Place birch door in village instead of wooden door
3. Wait for Zombies to attempt an attack

Expected Result:

• Zombies start breaking the door down to reach villagers

Actual Result:

• Zombies crowd at the door without attempting to break it, as though it was an iron door.

(On a side note, Villagers use the door properly.)