Pictures would help. Check valve is between flow center and heat pump? Two probes can indicate 2 different temps, measuring with 1 probe for in and out temp would be the way to go. Please get a needle thermometer and a needle pressure gauge to measure in your PT port. Please post the written reports you have. Taking the numbers for granted so far, everything above 30F is good loop temp, and 4F delta T suggests good heat extraction in 1st stage assuming that the flow is OK. Check that the compressor is still running once it reaches set point, not just the fan.