I tried making a quick redstone route down by creating a piston pattern going StickyPiston(down/up), redstone block, air, and repeat. In the screenshots you can see step by step me trying to figure out what's wrong and it seems that the piston is holding onto it's redstone charge without any other redstone charge.
EDIT: It seems the block coord of the piston holds onto the charge when the piston gets a direct source charge (remove, replace turns on again), but through another block (indirect) only while the piston is still there it holds onto the charge (remove, replace fixes)