While you're waiting for the wind to subside, wodpof, here are some other thoughts--
- any chance you have a leaky BBQ lighter or other butane-containing item in the camper?
- any chance you have a leaky aerosol container in the camper?
- any chance you have a source of acetone, gasoline, or alcohol vapors in your camper?
- any chance the rotten-egg smell is from the sink? (I once rented a campervan with this problem. A previous renter thought the camper sink had a garbage disposal and pushed egg down the drain. That was literally a rotten-egg smell!)
- suggestion: use google to search the web for "false alarms" for the model detector you have. I'm not saying you have a false alarm but the search results may give you other ideas of what the source of the problem could be.
- come to think of it, your propane tanks are in a separate compartment with venting in the bottom of that compartment to the outside. If your setup is like mine, you'll note that the door seal does not go across the bottom of the door so the heavier-than-air propane can exit to the outside and will not fall into your living quarters. Also the line going through the wall should be sealed. That means your problem isn't the tank valves or regulators or connections in that compartment. Still worth checking for your own peace of mind. And if it turns out you DO have a leak there, you will want to remedy both the leak and the function of the compartment.