I’ve been watching all these ARC issue threads and can’t help but notice that everyone has an LG OLED TV.
I’ve experienced this issue myself (I have a C8).
It’s always happens when my children fire up the TV to use it with some other device (WiiU, WebOS app, etc.).
I have found that if I turn on my TV to the Vero and let everything establish, you can then switch it to a different input or launch and app and it works.
It’s like the Vero is willing to surrender if it’s up, but if it’s not you have to pull the HDMI to break it’s hold on your setup.
I have my CEC settings configured so if I press a button on the Vero it wakes up and the TV and soundbar follow.
So I always turn on my system that way since I’m usually using the Vero.
If I switch from there to something else, then no problem, but if everything is off and my wife or children turn on the TV with the TV remote and then pick an input for a different device or launch an app, then no ARC.
I know that sounds weird, but maybe it helps you guys out in your pursuit to finding a fix or work around.
My setup is Vero > Samsung HW-N950 > C8 ARC HDMI
My children’s WiiU is plugged directly into the C8.