Even though your pressures look ok, when you vacuumed it down, did you leave it sit with the vac pump off for a good while to be sure it held vacuum? Sorry we don't know these things if it isn't written. One would expect if it was leaking, the numbers would be off.
I stopped relying on the rudimentary gauge on the vacuum pumps years ago and only vacuum with a "micron" gauge.
https://www.trutechtools.com/MicronGauges
Several times I have gotten to the end of the vacuum pump gauge only to discover later there was still a leak. If you can achieve 500 microns of vacuum (using the micron gauge obviously) or lower, you instantly know there is no leak. But that's beside the point of your problem.
OK you mentioned outside is 90 and vent temp is 68. Do we assume the air temp going into the AC is 90? If that's the case, you have a delta of 22°.
Over 20 is acceptable. Much more than that is hard to achieve. Now if you tell us the doors were closed and it was in recirculate and the air going in the intake was 80, you would have a problem.
From the photo it appears you have 64°. There are 5 divisions in a 20° span on the gauge therefore each division is 4°. Also, those gauges are notoriously wrong by varying amounts. It's always a good idea before using it, to put in a glass of ice water to be sure of 32°F/0°C.
Did you close the windows and put it on recirculate and see what the temp was after about 20 minutes? You have to remember we don't know how you tried it, how long you tried it and what was the temp inside the vehicle (even though the outside was 90°).
I was not aware of an expansion valve in these vehicles. Only an orifice tube. Is that what you meant by "black"?