Using /clone with the move parameter at the end on a powered rail, detector rail, or activator rail that is next to any redstone device except pistons will activate said device.
Reproducing:
Place blocks down like on the screenshot
Type the clone command so that the rail gets moved away from it's original position
Execute the command block
That's due to how redstone works internally. there is no way to fix this right now, so I recommend not cloning anything with active redstone signals.