I created a single biome world with the lush caves biome selected. I'm playing on the latest snapshot and I found a giant hole in the ground. Not to mention the trees are completely flat at the top.
How to reproduce
World type: Single Biome; Lush Caves
Coordinates: /execute in minecraft:overworld run tp @s -212.98 64.00 -65.75 405.00 49.95