Entities cannot pathfind inside of powder snow that has other powder snow blocks adjacently present

The Bug:

Entities cannot pathfind inside of powder snow that has other powder snow blocks adjacently present.

Steps to Reproduce:

1. Build the setup as shown in the attachment below. setup.png
2. Summon a creeper in the middle of the powder snow.
3. Switch into survival mode and approach the creeper so that it notices you.
4. Take note as to whether or not entities can pathfind inside of powder snow that has other powder snow blocks adjacently present.

Observed Behavior:

Entities cannot pathfind.

Expected Behavior:

Entities would be able to pathfind.