Currently, cave roots pick any block in a chunk as a candidate position, and are placed if an adjacent block is solid. If large features that carve multiple adjacent chunks are processed before the cave roots are placed, this results in floating cave roots since features are processed chunk-by-chunk.

One proposed solution is to have cave roots (and possibly similar underground decorations) use the CARVING_MASK Placement instead. This will ensure proper placement in caves (although, this means said decorations will not generate on or in any features that don't update the chunk's carving mask).

A simpler and probably more effective solution would be to simply bound the range of possible spawn points for cave roots to exclude chunk boundaries.