Normal?........I sort of guess it is acting the same as my 2012 Cruze.......Also my 2009 Miata.....My wifes 2008 Malibu.
Seems to me all these systems bleed a bit of heat.....likely because the air doors at the heater core don't seal as well as they could.
I have found that once I'm driving, I turn the temp full down (lowest temp) turn the fan on (position 1) and push 'recirculate'
Then I turn the fan off.
Following these steps makes it stay in recirculate, minimizing outside, pressurized air from entering the cabin.
Gotta do the steps with every restart though because the system defaults to outside air at the next startup.
I cannot think of a thing a dealer could do.
Rob