So I was making a water elevator and I wanted to switch it so I had the soul sand at the bottom I then go to the top and press a button that switched it to a top slab. When I tried going down it was still pushing me up when I replaced the block or moved the soul sand back then the slab when I was close range then it stopped pushing. TESTED: I tried doing testing and what I got is that when the soul sand is at y=63 and when I had a button at y=125 and redstone dust at y=126 and then I press the button to make a piston push the FULL BLOCK the pushing from the water was still occurring it worked at higher Y levels but not lower ones.

Edit 1: If you leave the world and come back it no longer pushes you up. It seems like it might be because of the players Y value and not the redstone's I will be testing it and posting the results later.