I actually took it to the dealer to check this. My first thought was that the thermostat might be stuck open but the service guy said it was definitely not stuck, otherwise it would have thrown codes. The coolant temp gets to just short of halfway in the normal amount of time like 10 minutes but it takes 20 minutes before it starts to blow warm air and it is warm, not hot. It blows cold before that and that’s with the climate control at the highest setting (Hi). If I stop, shut down and get back in a few minutes later, it seems to blow warmer but still not very hot. The dealer said that they reprogrammed the HVAC but I see no difference. How is yours working?