Air conditioner blows Hot air at the start
2014 MBZ E350 with ~70000 miles.
In most of the cases, air conditioning is working fine.
Problems show up when the car is parked in the garage ~85 F (summer in California).
When it is started with air conditioning on at 72 F setting, it feels like hot air is coming out as if the heater is on.
While suffering for 10 seconds or so, I set the air conditioning to max (lowest temperature setting).
When the air conditioning is set to maximum, it seems to engage and works fine after that.
What could be the problem?