Burning mobs don't walk into water when the water is on the same level as the entity

Summary:
Burning mobs don't walk into water from the side. This applies to both the source of water and flowing water. It seems that this does not always happen sometimes the mob enters the water.

Steps to reproduce:

1. Place the water so that burning mobs can be extinguished by walking on the side.

Observed results:
The mob stops at the water's edge.

Expected results:
A burning mob will always be extinguished in water.

Screenshots: