Not following your issue......side by side/both set to auto?
RM2852 is a 2 door fridge
Upper door///freezer
Lower door///food compartment
Only ONE control/display panel
CHECK LIGHT.....
that is a FAULT Light indicating fridge tried to swap to gas and gas FAILED to ignite/PROVE flame lit.
Turn fridge OFF then back ON to reset
If it trying to swap to Gas in AUTO then 120VAC is not being sensed...hence the swap to gas
Gas not igniting/proving (Check Light) then propane flow may not have fulled established (lack of gas usage) or bad ignitor/burner