Late response, but yes, the issues are persisting with the 8.0 release (at least for me). Sometimes CEC magically starts working immediately after using Kore to remote control Kodi, sometimes it takes a reboot, I haven't been able to spot a pattern there yet.
same here with RPi 1
I will try the hint from JimmySmith
Edit: I tried various setting but CEC is still not working reliable.
seems only solution at the moment is to use old firmware
There will be no major advantage right now, but over time add-on compatibility will become an issue. I got all changes for a Jarvis release completed in github (everything compiles) but there was a boot issue when I tried it on a box and since then I've either been travelling with work or on vacation so there's been no progress. Sadly it's a low priority vs. everything else here and someone with more time available needs to pick up the challenge.
please do not give up
I don't think that there is anybody available who can take over
nobody has your skills
I hope you will find the time to finalize and until then we will wait with patience
maybe you can make it as a christmas present 
That's odd, my apple tv sound on original firmware is fine through the HDMI on OpenELEC I have no sound at all.
then there is something wrong with your settings
check what you have configured in kodi
any news on this?
I'm about 75% done on an LE release which may/might get finished later in the month if I can spend less time on planes and more time at home.
great to hear that you are nearly finished with the release 
can't wait for it 
