When a block with a redstone torch on the side is powered, the torch should turn off and stop providing power, no matter what is underneath it.

Instead, redstone torches over a block without a flat top surface will be destroyed when powered rather than turning off. This does not apply to slime blocks, upside down slabs, glass, etc. but does happen with slabs, redstone dust, trapdoors, and most transparent blocks.

Steps to reproduce:
1: Place a block such that it has an empty space or transparent block diagonally below it to one side.
2: Place a redstone torch on the side facing the empty space or transparent block so that it is directly above it.
3: Apply redstone power to the block in a way that would normally turn the torch off.
4: The redstone torch will be destroyed and drop as an item.