The bug

Some blocks that I consider from the bottom to be firmly pass through the light if they are placed in the roof. These are, for example, blocks

• Enchanting Table
• End Portal Frame
• Stonecutter

It also makes Hopper, but it can be assumed that it makes sense for him to function. Stairs and slabs do not behave like this.

Reproduction

Build a closed hollow room, put one of the blocks in the roof. Then, to hide the light, over it. For example, using a Sticky Piston with a block of stone.

YT Video