1.21.9 introduced a fix to MC-173730 wherein shift-clicking a waterloggable block waterlogged that block. However, for interactable blocks that are waterloggable (such as chests, trapdoors, etc.), this introduces an issue where in order to waterlog them you have to place the water against a block face adjacent to the block you want to waterlog. This is a particularly big issue for chests, as they are almost full blocks.
Steps to Reproduce:
Place interactable and waterloggable block
Shift-click that block with a water bucket
Expected Result
The block is waterlogged.
Actual Result
The water is placed on the block adjacent to the face you shift-clicked.
Can recreate 1.21.11 Pre-Release 3
~ Happy to help!