In some cases, the Gigaset GS280 may open the camera app when the On/Off button is pressed once. To prevent this behavior, you can deactivate the "Jump to camera" option until the problem is solved: 

Android 9
Android 10/11/12
1. Open the settings1. Open the settings
2. Enter "Camera" in the search field
3. Open the menu item "Jump to camera"
2. "Intelligent assistance"

4. Activate or deactivate the option "Jump to camera"

3. Activate or deactivate the option "Quickly open camera" (For Android 10: Jump to camera")

(Note: By deactivating the function, the function to open the camera directly by pressing the on/off button twice is also not possible).