X90L ARC

My Sony X90L is connected to an Onkyo 575E amplifier. For the past two months, I’ve been having issues with ARC when using the TV built in apps.

Whenever I switch from one of the Onkyo’s inputs to a TV app, the Onkyo display changes to TV, indicating that it has switched to ARC. However there is no sound. The only way to get the audio back is to restart the TV and Amp multiple times. Sometimes it works after 2–5 restarts, while other times even 10 consecutive restarts don’t fix the issue.

To troubleshoot, I tried isolating the problem to determine whether it was caused by the TV or the amplifier. Without going into all the details, I found that the TV appears to be the source of the issue.

Whenever I disconnect the TV HDMI cables from ports 1 and 2, leaving only the amplifier connected to HDMI port 3 (ARC/eARC), then restart the TV ARC starts working immediately.

What’s confusing is that sometimes everything works perfectly even with all HDMI ports connected, which makes the issue even more confusing.

Audio Settings on TV:
eArc off not Auto since I’m using ARC (tried both).
Audio pass through set to Auto.
And all other settings that has on or off are set to off.