The Bug:

Cave vines can occasionally generate hanging on fences.

Steps to Reproduce:

• Generate a world with the following seed and teleport to the following coordinates.

• Caves & Cliffs 1.17.1 Datapack Preview
  World Type: Single Biome, Lush Caves
  Seed: 8653174682937665581
  Coordinates: /execute in minecraft:overworld run tp @s -8351.30 -10.88 78.97 171.86 -19.05

• Take note as to whether or not cave vines can occasionally generate hanging on fences.

Observed Behavior:

Cave vines can occasionally generate hanging on fences.

Expected Behavior:

Cave vines would not be able to generate hanging on fences.