Why is onDestroy always called when another activity starts?

Question

Android

Hello.
Came for testing device Nexus5 with Android 4.4.2. Delivered application for testing. When starting a new activity

startActivity(new Intent(this, SettingsActivity.class));

The past one constantly calls onDestroy. this is how all activities behave. In the manifest in activities

<activity
            android:name=".ui.SettingsActivity"
            android:label="@string/settings">
        </activity>

If you just turn off the screen, then only onStop works properly. This application works properly on other devices - Nexus7, Huawei 8950, Nexus4. Then I decided to update the firmware - updated to 4.4.3. Same thing, no change. Then I updated to 4.4.4. No changes, onDestroy still fires. The phone is clean, it only has this application.
Tell me where to dig.
Thank you.

Answer 1

Hello,
Check Settings->Developer options->'Don't keep activities' item.