2019 FE Photon Red
As was posted earlier, if you open the door, i.e. after pulling into your garage, get out and leave the car it will stay unlocked.... When I get back from a trip and pull into the garage, the doors stay unlocked for eternity. That is normal behavior.
When I then use the new app to lock the car, then unlock it, the car auto-locks if I don't get in it. This takes about 30 seconds.
If I then use my keys to unlock it, it will auto-lock the car after 30 seconds.
If you unlock from the outside with either the app or the fob and do not open the door, it will relock automatically.
What you are describing is standard behavior.