2018 Chevy Camaro SS AC intermittent – works sometimes, blows warm other times

I’ve got a 2018 Camaro SS and the AC is driving me crazy. Sometimes it blows ice cold, other times it’s just warm air, and there’s no pattern to it. It doesn’t seem to matter if I’m driving or idling, hot day or mild evening. I’ve noticed that if I turn the AC off for a few minutes and then back on, sometimes it starts working again. I took it to a local garage and they said the refrigerant pressure is fine and the compressor clutch is engaging, so they’re not sure what’s wrong. They suggested it might be an intermittent electrical issue with the climate control module or a sensor. I’m looking for a sharjah camaro ac repair shop that actually understands these cars and has proper diagnostic equipment. Has anyone here had an intermittent AC problem on a Camaro or similar GM car? What ended up being the cause? I’m worried it could be the compressor starting to fail, or maybe the expansion valve sticking, or even a bad pressure switch. The car has 55k kilometers on it so it’s relatively low mileage. I don’t want to start throwing parts at it without a proper diagnosis. If you know a good AC specialist in Sharjah for American muscle cars, please let me know. I really don’t want to take it to the dealer because I know they’ll overcharge me. Thanks for any help.