Vines can generate floating when intersecting underground structures

The Bug:

Vines can generate floating when intersecting underground structures.

Here is an example:

Version: 1.21.7

World Type: Single Biome, Lush Caves
Seed: -6146314301770596738
Coordinates: /execute in minecraft:overworld run tp @s 5182.52 9.16 2376.87 -399.75 14.89

Steps to Reproduce:

1. Generate a world with the world type and seed provided above and teleport to the given coordinates.

2. Look closely at how the vine has generated.

3. Take note as to whether or not vines can generate floating when intersecting underground structures.

Observed Behavior:

Vines can generate floating.

Expected Behavior:

Vines would not be able to can generate floating.