Put the summary of the bug you're having here

What I expected to happen was the lichen to cover all sides of the corner, then drop 1 when broken.
Describe what you thought should happen here

What actually happened was the lichen only covered one side of the corner and, if another was placed in a different block in the corner, they both broke, and only 1 item was dropped.
Describe what happened here

Steps to Reproduce:
1. Have a corner of blocks that glow lichen can be placed on (for example, one at 41,-24, 163   and another block at 40,-24,164)
2. Place a glow lichen in the corner on one of the two blocks, then place one on the other block in the corner. This will now make the lichen break together.
3. Break the lichen. It will only drop 1 item, even though you placed 2.