I know this a mechanical automatic watch - so it has a sensor and only works when you have it on. However, nowadays, it doesn't seem to work. I fix the date and time, wear it, see the second hand working, but check back later and the time has not changed and the second hand has stopped moving. I have twisted the knob and it'll start working again, but just for another minute or so, and then stops working again. What do I do??

Watches - Giorgio Armani