Waterlogged blocks in structures spread to other waterloggable blocks when loading the structure

The bug

When loading a structure containing a waterlogged block, that waterlogged block will spread its waterlogged state to other waterloggable blocks next to or below it. This repeats for those newly waterlogged blocks.

How to reproduce

1. Download the attached waterlogged_test.zip datapack and install it
2. Place a structure block in the world
3. Load the structure test:waterlogged_test
4. All waterloggable blocks are waterlogged, even though in the waterlogged_test.nbt file in the data pack only one block has waterlogged=true.

Example

Here is an example in video: https://youtu.be/s_VxTfJxtuw