If you have a factory installed remote start, then it is integrated into your key fob. Upon unlocking the door, you should have 60 seconds to put the key in the ignition. Longer than that, the engine will shut off. If you don't get the 60 second delay before shut off, go to your service department.
If you have an extra remote start fob, not integrated into your key fob, this is a dealer installed remote start. These are known to have problems and are no longer dealer install items. If you have this type, then you will most likely have to go to your service department.
If your remote start was installed aftermarket, not by the dealer, then you need to return to where you got it and ask them this question.