Check your manual to see if you're head unit has a specific setting for when the antenna is to be used. Also, perhaps the power for the antenna was connected to the power for the radio instead of a separate power antenna wire in which case the antenna will go up when the unit receives power. And on the other hang it could just be the head unit itself. Just because it's a newer unit doesn't mean it'll carry all the same features as previous units.

So first check a manual for settings, and if there's nothing specific, check the wiring.