This may not be the correct answer, however you can try it to see if it works.
*** CAUTION USE AT OWN RISK ***
The clock mechanism is fasten to the clock with a nut just behind the hands. it is possible that the mechanism has turned a few degrees clockwise. You may want to try to turn the mechanism counterclockwise from the back, just a little at a time to see if it brings your chime back in sync. If this doesn't work or causes damage to your clock you have tried this solution at your own risk. I would not come up with a solution if I thought it would cause any damage but I feel I should state the warning in anycase
Michael, September 2016
