Mobs can't leave the boat when their head in the water

When mobs head in the water, mobs should leave the boat like Java edition.

How to reproduce:

1. Put the campfire on the block
2. Put a boat on the campfire
3. Get the creeper on board
4. Use water bucket to create one block water to cover the mobs' head
5. observe if the mob can leave the boat

Observed Results:
The mobs can't leave the boat in bedrock.

Expected Results:
The mobs should leave the boat like java edition.

Note: 
When you save your world and open it again, mobs can leave the boat, so it's a bug