The Bug

Every zombie is able to break doors, but they are supposed to only have a specific chance to be able to break doors, which also depends on the local difficulty like on java edition. This affects normal zombies, drowneds and husks.

How to reproduce:

1. Make sure to play on hard difficulty and have gamerule mobgriefing set to true
2. Lock up a villager and place a wooden door
3. Spawn a zombie
4. The zombie will be able to break the door
5. Kill it
6. Spawn a new zombie and repeat that over and over again

Expected result: Not every zombie will break the door.
Actual result: Every zombie broke the door.

I noticed this in survival it happened very often that a zombie broke a door, because of this bug.