Could be propane regulator acting up at elevation....how do the flames on stove top burners look? Strong steady.....does water heater fire up without issues?
Could be fridge Flame Sensor.......The spark electrode for the main flame (it's a small flame but not a pilot it's the main flame) ignites the main flame AND is used as a flame prover back to circuit board.
If it is not in proper position (directly over flame and engulf by flame),
if it is not properly gaped (1/8" to 3/16"---tip to burner),
if it is dirty (carboned up)
OR if burner slots are dirty the flame will not stay lit.