The observer will output a 2 tick signal normally but will output a 1 tick signal when rapidly activated.
Steps to reproduce:
- Place an observer
- Place a sticky piston with a block on the output side
- Place a repeater in front of the observer and hold down
Gif of bug: https://gfycat.com/PoshMistyAmericancrocodile
Gif was posted by a moderator NOT me