On April 30th I received a new drone. I checked the safety settings, it was configured to use RTH if the signal was lost. On May 1, I checked the safety settings, there was a setting: Descend.
This has happened twice since the beginning of the year when this setting changed on its own.
What could be the reasons for this? This may result in the loss of the drone.

Hi, Drone.Hunter. Thank you for reaching out. Just to confirm, is this for DJI Air 3? Also, you set it to RTH if the signal was lost but it was set to Descend without you changing it. Can you please confirm what RC you have and if there was any firmware update before it was changed to Descend?

Air 3, RC2
Update FW Drone from v01.00.1200 to v01.00.1300
Update RC2 from v02.00.0500 to v02.02.0000

Drone.Hunter Posted at 5-1 22:27
Air 3, RC2
Update FW Drone from v01.00.1200 to v01.00.1300
Update RC2 from v02.00.0500 to v02.02.0000

Thank you for the reply, the aircraft will not automatically change its setting; the factory default is RTH (Return to Home). We suggest to try connecting to the aircraft, changing the setting back to RTH, and then restart it several times to see if it reverts to Descend.

I tested it and the setting didn't change. But I didn't fly, it's raining today. Maybe other actions with the Drone affect this.

If you have updated the Fly App, drone or RC  then settings will change

Suren Posted at 5-3 12:10
If you have updated the Fly App, drone or RC  then settings will change

I have updated the Mini 3 Pr, RC many times. This has never happened before.
And according to the administration, RTH is the default setting.
But a fact is a fact, and we need to understand how to avoid accidents with a drone in the future.

Being at home, the problem could not be reproduced. Today I flew for 15 minutes, after which I carried out various tests with the drone camera at home without taking off. And after that I saw that the setting switched to “Descend”

Drone.Hunter Posted at 5-5 02:04
Being at home, the problem could not be reproduced. Today I flew for 15 minutes, after which I carried out various tests with the drone camera at home without taking off. And after that I saw that the setting switched to “Descend”

Thank you for the update, Drone.Hunter. We have confirmed with our relevant team that this option will not change automatically. Please keep monitoring and give us feedback, for example, please set it to RTH first and then check that option before every flight, if you notice that the options have automatically changed again, please export the App log and the exact date and time when this issue occurred. Please keep us posted.

I reset the settings of the Drone and the Remote Control, I will watch.

The setting is recorded in the .txt flight log. If you go through those you should be able to find where the setting changed.
Scan the entire relevant column in each log. I think it is entitled Failsafe or similar.

I erased all my waypoints

Drone.Hunter Posted at 5-6 07:55
I erased all my waypoints

Does that erase the flight logs ?