redstone torch key not working

When I was testing some of my redstone machines in my redstone testing world I noticed that the redstone torch key was not working, the piston underneath the block was not extending I'm using Asus Zenfone Go or Asus Z00D 5.1

What I expected to happen was... :
The piston underneath the block should have extended when I place a redstone torch in front or on top of that block.

What actually happend was... :
The piston underneath the block did not extend.

Steps to reproduce:
1.place two blocks one of those being one block higher.
2.place a piston underneath the lower block.
3.place a redstone torch on the face of the higher block where the lower block is placed. The piston underneath the lower block should have extended but it didn't