Official comment
The Mini 3 uses Virtual Stick controls instead of waypoints which means that the app is issuing the navigation control commands. If the app crashes it can no longer do that.
Map Pilot Pro flights must begin on the ground so if the app crashes you would need to hit the return to home button and reset.
1.5.2 should be better since DJI fixed a bunch of issues. Make sure your firmware is updated to meet the requirements listed on the Installations page.