The attached images display a binary counter with a one tick pulse provided to its input. When close to the counter there is no issue, but when I move a few chunks away from it the blocks being moved by the pistons start to duplicate. This could obviously be used to create unlimited resources and poses an issue for redstone contraptions. The first image shows a clear circuit design; the second shows chunk stats; the third shows the circuit from three chunks away; the forth shows the circuit after the bug has taken place and the fifth image shows the input circuit.

I have observed this in both single player and multi player (realms), on both windows 10 and linux 3.19.