Hi,
did you tried some of the basic commands from here: Raspberry Pi: Power On / Off A TV Connected Via HDMI-CEC - Linux Uprising Blog
like turn off/on the tv via HDMI-CEC from the PI? or switch the active source with this: 'as' ? I would go with some easy commands to see if the hdmi-cec is working correctly, out of this image for me it is interesting why the Vendor is not known...
Second option to check. Install add-on Keymap Add-on:Keymap Editor - Official Kodi Wiki (i used this video
For me I have a samsung tv remote with some pre defined buttons, like Netflix, Prime (i am not happy with it, but that's the way...) and unfortunately the button "Exit" in my old Samsung TV was the simple command to go back, navigate back, previous menu... now in this remote this is not working so i needed to remap it to button A(red)...
Last but not least, i have a Samsung TV with this new Tizen OS (not better, but once again that's the way... ) , so in this newSamsung (pictures attached) look-a-like setup when i connect my PI over HDMI to the TV then the HDMI-CEC setup starts... and there is a predefined list of hardwares like blueray players, AVs, XBOX, PS4, soundbars, lot's of stuff... but PI only works for me if I select "PC"... no clue why, as said before this only in the newSamsung Tizen OS.