Screensaver / Standby change TV-Source with CEC

  • Everytime my Raspberry Pi 3 Model B activates his screensaver (10 Minutes timer), it changes the TV HDMI Source to himself.
    It is very disturbing while watching medias on another HDMI-Device.

    Did I set the wrong settings?
    It should'n grab the controll, when it goes into standby.
    It should only grab the controll, when it wakes up.