Common problem is the partition between the intake and exhaust falls down because it is only a friction fit.
If you removed the cover you should have seen it.
With the cover removed you can see the thermistor he was talking about. It is a wire pushed into the fins of the evaporator. It’s there to detect ice buildup.
Pull it out of the fins and just let it hang. Then see what your temp difference is.
If this helps, run the unit and, with the thermometer find the warmest spot on the fins and insert it there
__________________
|