Carbon Monoxide Detector

My bedroom carbon monoxide detector went off last week while on a casino parking lot. There was very little wind at the time with no obstruction near the exhaust and the generator had been running for 10 hours when the dectector went off right as I laid down for the night. My exhaust is just behind the cab on driver side and bedroom in my C is rear. I shut of generator opened windows and door until detector would reset without going off, then restarted generator. I then got the carbon monoxide detector from the living area and put on a shelf in the bedroom as additional safety precaution for the remainder of the night which went by without another issue. *I added the bedroom carbon monoxide and smoke detectors soon after purchasing the motorhome because I was not comfortable with only having detectors twenty feet or so from the bedroom.