Steps to reproduce

1. In a 2x1x2 area place a bottom slab in the northwest corner, then planks in the other three spots. Enclose this area with some other block to prevent excess water flow.
2. Waterlog the slab.
3. Stand on the slab and run /clone ~~~ ~1 ~ ~1 ~3 ~ ~ filtered normal planks.
4. Break the planks in the new location.

Expected result

Only the planks are copied. Nothing is left in the new location after you break the planks.

Observed result

The planks and the second-layer water are copied. When you break the planks, water flows out of the waterlogged air. See Clone filtered does not filter second block layer.mp4

Impact: This bug makes /clone...filtered useless if the build you wish to clone has any waterlogged blocks. The cloned layer-2 water will waterlog almost any block at the destination, such as air, stone, or fire.