Hi,
Your not going crazy - it is a kind of setting you have changed.
Holding the auto button on the climate control console for approx 5 seconds will re-engage the dual controls where they both change via the right hand adjustment button. You will notice this has worked because if the temperatures are set at different levels the left hand temp will jump to match the right hand temp when this has worked.
However, you should note that adjusting the temperature from the left hand adjustment button (ie if a passenger changes their temperature) will desync the dual control system. Only takes 5 seconds to re-engage though.
Hope this helps and is clear enough to follow.
Mike
*took so long to write it that someone beat me too it.
bugger...