I've been working on creating a two block wide staircase using sticky pistons in creative mode that is three blocks high. I currently have 5/6 stairs working but the middle step on the right side is having issues.

When I step off either pressure plate there is the pause so that you can go up the stairs,  but the problematic block flickers briefly between on and off, before resynchronising and turning off with the rest of the blocks.

The circuits are identical on either side and I have extensively monitored the circuits and can detect no anomaly.

Any help would be appreciated