The bug

If you blow up a (naturally-placed, at least) end crystal, its hitbox will seem to remain after it is destroyed and won't let you interact with the 2x2 area it was once on. Nothing shows up with /say @e[distance=..2] or when using F3+B, though (Image 5).

How to reproduce

1. Place an end crystal on bedrock (Image 1).
2. Punch it so it blows up (Image 2).
3. Examine the spot where the end crystal used to be. You cannot punch the bedrock (Image 3) or the closest half of the blocks next to it (Image 4).