1.15.2, 1.16.4, 20w46a, 20w48a, 1.16.5, 21w11a, 1.17.1
While not technically a bug, it is surely a game-breaking unintended issue. This is a problem because it prevents using a beacon there. Beacon beams can go through bedrock but not netherrack, and the random spotty unnecessary bedrock generation of the bedrock roof (and ground) sometimes make a block get encased in bedrock. I tried breaking it with explosions but to no avail.
How to reproduce
/execute in minecraft:the_nether run tp @s -35.57 119.58 32.50 6.39 -90.00
- relates to
MC-4405 Beacons work inconsistently in the Nether