If you build the circuit from the picture I provided, you will see that the sticky piston doesn't leave its block in front of it like it should when given a one-tick pulse. It instead pulls it back, which makes it seem like it just got a two-tick pulse.

This bug seems to only occur under very specific circumstances. The arrangement shown in the picture is one of two I've seen, and that leads me to believe it's not a case of weird quasi connectivity. Lengthening the wire makes it disappear too.

This has already broken one of my inventions, so I hope you can fix this soon.