I would bet you are experiencing a couple of issues. One is that the refer is indeed being blown out in transit. This can happen from a couple of things. If your refer is on the roadside of the coach, passing semis, or on coming traffic can create a gust of wind that could blow out the flame. The other issue is that there could be so much air rushing into the compartment that it is not blowing out the flame, but it is allowing the flame to be disturbed to the point it does not transfer the heat to the refer.
In either case you will need to look into a baffle of some sort. Some folks have had good luck with a sheet of metal that is permanently installed. Others have just used the blue washable AC filter mat and installed before travel and removed post arrival to stop the burst of air from causing the trouble. The filter fluff baffle MUST be removed f not towing or the refer could be damaged.
WBCCI #5501 AIR # 49
1978 Argosy 28 foot Motorhome
Wise men talk because they have something to say; fools, because they have to say something. -- Plato