Bubble Columns Do Not Update when Blocks are Swapped

Use a piston block swapper to push a magma or soul sand block where the other block used to be. 

The bubble column will never update.

 

So what happened is I made a block swapper trying to create a switchable up or down bubble column, but the column is stuck as an "up" column, even though there has been a magma block at the bottom of it for (real life) days.