Have warm fridge, cold freezer on propane
I have a Norcold N7X 2 way (AC and propane) fridge in my 2019 Jayco. The freezer is very cold (5 degrees), and the fridge is very warm 55 degrees. I don't use AC, this is just on propane. There is a strong blue flame, I changed the thermistor, trailer is level, there is no yellow powder behind the fridge indicating a leak, ventilation behind the fridge is fine, it is not blocked. Every source I have read or watched online says this indicates a clog in the coolant lines, but I have a hunch this is not the problem. A friend has the same problem with his Dometic, he removed his fridge and turned it upside down to "burp" the coolant lines to free up the clog, and it did not work.
One thing that I read, and is interesting, said that the aluminum cooling fins in the top of the fridge have a backing plate that is attached to the coolant lines with a thermo conductive mastic. Sometimes this mastic turns dry and crumbly, and no longer conducts the cold. It said I could unscrew the fin plate, and look behind it, but I don't think I have seen these screws inside the fridge.
Does anyone have an idea?