[Mojang] Bjarni Gudmundsson

Large dripstone structures can be generated outside the caves

Burning mobs can still destroy powder snow when gamerule mobgriefing is disabled

Copper Ingots are no longer grouped in the crafting table

Weather can sometimes be incorrect within a biome

Icebergs go all the way to ocean floor.

Withers do not move down to follow the player when the wither's health is half or lower

Wither Skeletons can only spawn on Nether Bricks

Weather effects appear in caves and structures in 1.17.1 worlds loaded in 21w43a