Deserts in 21w37-41a (all 1.18 snapshots) generate with little to no sandstone between sand and stone. This often leads to mountains and even just hills with large amounts of exposed stone under the ~3-block sand layer.

What I expected to happen was:

A layer of sandstone, about 3 or so blocks deep, should generate below the sand layer in deserts.

What actually happened was:
Little to no sandstone generates under sand. This is noticeable on mountains, where stone will often appear directly under sand.

New 1.18 cave entrances also have weird sandstone generation in some parts. It generates on the surface around some caves in 21w41a.

Steps to Reproduce:
1. Generate a new world, either single biome desert or normal. I've found this issue in both types.
2. Find a desert and either dig down or find a hill.
3. You should find little to no sandstone under the sand layer.

Pictures 1-9 are from 21w41a. The next two are from 21w40a, and all the last 4 are from 21w37a. In the 21w41a screenshots I also dug a square hole until I hit stone. I hit little sandstone along the way, with the only sandstone being some that generated around a water cave.