I have created this model on the community realm, so you can check it out. Co-ords 253, 113, 76

Basically an observer triggering a T-Flipflop circuit. The T-FlipFlop is build of 3 droppers and one hopper (classic design) .

The observer is set to watch sugarcane growing beneath it. Facing down and strongly powering the dropper above it.

The output of the dropper at the rear is taken via comparator to power a sticky piston to break the sugarcane.

On single player this works ok most of the time. On a realm the observer appears to be triggering the T-FlipFlop twice per observer pulse resulting in the creation of an oscillator/clock action. This should not happen.

On single player if you place a second observer on the side of the first observer (output facing away from contraption) the Oscillations run a what looks like 1 tick.

On single player if you place a second observer on the side of the contraption this time observing the Comparator, Oscillations will happen at a 3 tick rate.

Non of these behaviours should occur.

PS a dedicated realm for these demonstrations would help enormously and save you the time of trying to repo these issues yourselves.