On modern Samsung smartphones and tablets, a so-called Game Booster or Game Launcher is installed, which should support you in playing games. So screenshots and screen videos can be taken with the software.
To enable you to open the Launcher quickly, two additional icons are displayed in the navigation bar. If you don't want this, because you are neither using the Game Launcher nor the Game Booster, please deactivate them as follows
Disable Game Launcher
1. open the Android settings
2. navigate to "Advanced Functions".
3. there deactivate the "Game Launcher" using the slider.
It is possible that the Game Launcher is now deactivated, but you can still see the icons in the status bar. If this is the case, you can also remove these two icons as follows
Disable Game Booster
1. open the settings again.
2. navigate to "Apps
3. go to the three-point icon in the upper right corner and then to "Show system applications".
4. search for "Game Booster
5. select "Permissions" and remove all assigned rights from the app
Afterwards, no more Game Launcher or Game Booster icons will be displayed in the navigation bar.