A/C blows hot air on the drivers' side and cooler air on the passenger side?

The truck listed above is an LTR model. I’m having a few problems with it but let’s start with one. A/C blowing hot on driver's side vents and cooler on passenger side. It does this in manual or automatic setting. I can get it to blow cool out both sides, but setting is on lowest fan setting and temperature is set all the way down to low. I don’t have a check engine light on. If I turn the fan setting higher it either gets hot like I have heater on, or it blows like it’s the fan on. Also, the fan on my truck should have a high revolution fan and just a reg fan. The high fan is not coming on. I have had transmission work done to it (transmission went out, transmission shop put in new one) I think I heard them say they were putting a lower temperature thermostat.