Can place Grass Path at "invalid" locations

You can pick block grass path and place it under blocks, when you then update the block (by placing a block next to it for example) the grass path will become dirt (intended).

Expected:
The grass path would instantly be replaced by dirt, not after a block update.

Steps to reproduce:

1. In creative pick block grass path.
2. Place a block (for example planks)
3. Place the grass path below it.
4. See it doesn't change to dirt.
5. Place a block besides the grass path.
6. See it change to dirt.