Manual says push to open.
Yeah i was thinking about something like this bit.ly/2W1WKpS it keys to the factory key so you don't have to have an extra key. Although i was thinking perhaps it had an electronically locking fuel door that locked with the vehicle, that would be cool but more than likely it is just a push door.Push and it pops open. You could always add a locking gas cap for security.
I have this same issue. I now look back to check after exiting a car washI really dislike the push open door, wish Jeep made it with a better latching mechanism. I don't really want a locking cap, I just want the door to stay closed rather than opening anytime anything bumps into it. Car washes for example will open your fuel door. poor design imo.