Summary:
On the top and vertical sides of the dirt path and farmland you can place blocks that require support. Because of this, these blocks fly on the dirt path and farmland and break parity with Java (this is described in many reports about block placement problems).
The exception should be farmland plants which are described in MCPE-167356. All other blocks such as stairs, redstone, torches, buttons and any other blocks that require a supporting block must not be placed on the top and vertical sides of the dirt path and farmland!

Steps to reproduce:

1. Place dirt path and farmland blocks.
2. Place blocks on them, on the top and vertical sides, that require a supporting block (redstone, ladder, vine, glow lichen and sculk vein)

Observed results:
You can place blocks on top and vertical sides of dirt path and farmland blocks.

Expected results:
Blocks will not be placed as these sides are not full.