Redstone doesn't go down or up a block "staircase" made out of glowstone

If you place redstone in a "staircase" shape on glowstone, the one that is not it the same Y level of the other one will not be powered.

What I expected to happen was...:
The redstone would go down

What actually happened was...:
It didn't

Steps to Reproduce:
1. Build a block "staircase
2. Put redstone on all the blocks
3. Power one piece of redstone