Well whatever it is its getting worse Like 64° today. I wasn't able to try my stock 107 because my wife had a list of chores for me to do. But I am leaning towards the monovalve because even the outlet of the heater core is hot which should be being cooled by the evaporator. I even did try to pinch it off but my pinch pliers are really too short for the hoes diameter.
I did order a new monovalve, Its not MTC but a company allegedly as bad. Vollig - Heavy Duty
But who knows, maybe they got this part right.