Sand and Soil Shower. P1

In the video, I'm in the creative to better understand the error, and the error itself affects all modes.
The video shows:
If a player (with boots to enchant the speed of the soul), stands on a block of sand or the soil of souls, then he will have acceleration. And when the player leaves the block * shower*, then he ^ should stop the acceleration effect^, but this does not happen. And you can remove the acceleration effect only when you step on any other block.