Hopper & monster spawner causes dirt under them

Dirt is caused under the hopper and mob spawner blocks, hopper is not covering the grass fully, and mob spawner allows light for grass.

How to re-produce:

1: Go into a flat world, place down hopper and mob spawner.

2: Set ticking speed to 9999, then exit out and go in again, then set it back to 1.

3: Notice how there is dirt under the two.