Entities cannot pathfind out of the lowest level of flowing water that is one block deep

The Bug:

Entities cannot pathfind out of the lowest level of flowing water that is one block deep.

Steps to Reproduce:

1. Build the setup as shown in the provided attachment. setup.png
2. Using a spawn egg, summon a villager in the water while looking at the diamond block.
3. Wait for the villager to notice the nearby workstation.
4. Observe the villager's behavior for a while.
5. Take note as to whether or not entities cannot pathfind out of the lowest level of flowing water that is one block deep.

Observed Behavior:

Entities cannot pathfind out of the lowest level of flowing water that is one block deep.

Expected Behavior:

Entities would be able to pathfind out of the lowest level of flowing water that is one block deep.