The propane detectors are sensitive to various other gasses in addition to propane and sometimes can be there triggered by things like aerosols, pets with gas, etc. They also can trip if the 12V system voltage us low.
A gas leak at a fridge generally ought not readily cause alarms as the gas parts are in the outside vented section and sealed off from the interior. Check that all the stove and oven controls are off. Maybe the oven pilot light is out but still on--quite a few RV oven pilots do not have any sort of flame sensor interlock for the pilot itself, but only for the main burner.