Up date, I have three drone batteries and the results have been the same. Use the app to change the camera settings while connected to the drone. Turn everything off for a while the camera settings I set are still there. Do the same a few hours later and the camera and video settings are gone , but not all the other settings that were also set using the app such as return to home height etc.
I also have the app on the phone I use daily; this phone has never been connected to the controller. I connected this phone this morning with the controller and switched on the drone and all settings were there except once again the camera and video settings. This leads me to believe that most if not all settings are not saved in the app and could be saved in the controller. But why then would the camera settings revert back to default and not all the other settings that were changed.
Google play store app is v4.3.37 but if you look on the DJI download site the version is v4.3.46. I have used DJI assit and reinstalled the firmware for both the drone and the controller and that has made no difference. I have done the same with the app on all three phones I own.
A strange event just happened, I connected everything up for the third time this morning and received a warning that there was an incapability issue and I clicked update and it was showing an update was being done on the drone 01.04.0500. I have since looked using the app of the versions on the drone and controller and both are showing 01.04.0500.
I will check again later today to see if that has made any difference, but both were reinstalled using the DJI assistant a week or so ago and today was the first time I received this warning. I last flew the drone four weeks ago and it performed well, it was only when I downloaded the footage when I noticed the camera and video settings must have changed at some point.
I do not believe any settings are saved on the SD card; most camera minded people always format their cards after they use them each time.