Title. Not sure why this is happening, but I can only make the piston move if I change the delay of a repeater by clicking on it. I am trying to use this with a bubble column elevator, So I can't change the delay as the water will wash all my redstone away.
You need to give the pistons a block update, I did so using observers. (You can use one if resource limited) though this design seems to suck me through the ground, I included another design I made in the world download also.
The repeaters are on a zero tick delay It should be higher, and the lower half is unchanged.
World Download @ Cords: 4 56 44
Here is my design which I think works better, could be made more compact for sure.
The obsidian near the swapping blocks might be needed if you have this above the ground (as it might be pushed away)