Not sure if this makes a difference, probably does, try setting the thermostat to COOL not HP, in HP the unit is trying to heat not cool. I'm not an AC expert but from what I know, you are running the AC process in reverse, extracting heat from ambient air to heat the interior rather than extracting heat from the interior and dumping outside.
2015 27FB International Signature "Danielle"
ProPride / 16" wheels / 600W solar / 864 AHr Lithium
Victron MultiPlus Inverter / BlueSolar / ColorControlGX / BMV 702
Porsche Cayenne Diesel