Smart Unlock (with push button start)
WARNING: This page is about a different car, the 2021 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
The smart unlock feature prevents the vehicle from electronically locking when a passive key is left inside the vehicle. When the doors are electronically locked while a door is ajar and then closed, the interior of the vehicle is scanned for a passive key. If a valid programmed passive key is detected inside the vehicle, the BCM unlocks the doors and chirps the horn twice.
To override the smart unlock feature, lock the doors using the keyless entry keypad, the door lock cylinder or another valid programmed passive key.