Original solution from her: https://forum.kodi.tv/showthread.php?tid=352993
- SSH into kodi, usually root and libreelec ( should change this asap)
- Stop Kodi via the GUI or terminal with "systemctl stop kodi".
- Edit the CEC Adapter config file in "/storage/.kodi/userdata/peripheral_data/ via the terminal". This configuration file name varies based on the adapter. For example, for RPI, it seems to be "rpi_2708_1001.xml", and for a Pulse Eight CEC-Adapter, it seems to be "usb_2548_1002_CEC_Adapter.xml".
- Change
line "device_type = 1" to "device_type = 4". This will force the adapter to register as a Playback device rather than a Recording device. Restart Kodi by restarting the machine or running "systemctl start kodi" in the terminal. May need to restart TV or go into CEC settings and Discover
Edit: The most important part got left out.