Another more universal problem could be that your compressor is failing, so too much load at idle when the HVAC system tries to engage the compressor clutch, but if it seems to work okay when given light throttle, then I'd lean towards the PCM firmware update being the solution, again if it is the 3.5L NA engine, and being one of the affected 2013-2015 model years.
Just for the heck of it, I'd see if I could replicate this with it parked and hood up, just to make sure that when it happens, you aren't having the compressor seize up and the belt slipping, but if that happens it may only do so for a moment at a time, because that PCM firmware issue I mentioned, is evidence that the system will disengage the compressor clutch if it senses too much engine RPM drop.