Bamboo grows in lots of inappropriate places in Bamboo Jungles

Steps to reproduce:

Create a Single Biome world with Bambo Jungle selected as the biome.

Observe that bamboo, can, and will, be a little overambitious in where it decides to grow.

World type: Single biome
Customize: Bamboo Jungle
Seed: 3782446731170602800
Coordinates: /tp @s 387 68 -30