Planting a 4x4 spruce or jungle tree bellow y=0 doesn’t grow.

Dark oak does work.

(I assume this is 1.18 beta. As I turned on experimental mode)

reproduced by:

1) clearing out a chunck

2) placing 4 saplings of spruce on 4 dirt blocks in center of chunk where the height is less than 0

3) bonemeal the tree

4) tree doesn’t grow.

Expected  results:

given enough space the tree should grow below y=0

note, if I pillar up the dirt to 0 or greater, then it works.