[M3R8]

I'm not an AC specialist but the job of the compressor is to compress the gas, and it appears to be doing it just fine in your system. I very much suspect your problem is elsewhere and wouldn't even think about replacing this expensive part which involves quite a bit of labor.

If you have the V8 as your profile suggests then it's an engine out job just to replace the compressor due to one bolt being inaccessible. On the V10 it's possible to replace without removing the engine.

Reading about the expansion valve here:
https://www.swtc.edu/ag_power/air_conditioning/lecture/expansion_valve.htm

Says: "If the area cooled by the evaporator suddenly gets colder, the heat transfer requirements change. If the expansion valve continued to feed the same amount of refrigerant to the evaporator, the fins and coils would get colder until they eventually freeze over with ice and the air flow is stopped."

So this definitely sounds like your culprit as it explains your situation exactly. Sounds like replacing it would be your best bet at this point.

Important to note that with every refill you usually get a small amount of oil added into the system together with the gas, this is normal, but be aware that too much oil is also not good. I recommend that you ask your AC shop to do a system flush before the last refill once the new valve is installed, a flush would remove excess oil and any other contaminants in the system.