Shutdown does not work when Kodi autoboots with the Pi

Hey guys!
I am working on getting a Raspberry Pi 3 with the Official 7″ Display to work with Kodi 17.1 installed on Raspbian Jessie Light to put it in my current car project.
I decided to use a custom build instead of using something like OSMC because all of those versions were not able to shutdown the Display when shutting down the Pi (The Display always started showing white and black lines).
Now Jessie Light is installed and Kodi 17.1 itself is working just fine, but when I put Kodi in the autoboot, the shutdown button of the Estouchy skin is not shutting down the system as it is supposed to, but only stops Kodi. The option to set the button to shutdown under “Options>Power saving>Shutdown function” is even missing and only “Quit” and “Minimize” is available. If I start Kodi manually after the Pi boots up, The option “Shutdown” is there and is working correctly.
I put Kodi into autoboot by adding these lines into “rc.local” (also tried longer sleep times):

Code:
sleep 2
su pi -c 'kodi & '

I would really appreciate any help being it a different idea to put Kodi into autoboot, fixing the skin settings or maybe even telling me how install-ready versions like OSMC can turn the display off when shutting down the system!

Zurafta