I spent HOURS trying to resolve this.
I solved my problem.
It seems each issue is unique, depending on your equipment and how you set it up.
Hopefully this helps some of you because it was so simple I laughed when I fugured it out.
My source is Amazon FireTV Cube.
I simply redid the "Set up my Equipment" Wizard (through the amazon FireTV cube)... Turns out that it ERASED my AR Receiver from the equipment one day which messed up the HDMI ARC control.
The equipment wizard let me add my Yamaha receiver and designate TV input AND AV Receiver inputs. (make sure receiver has ARC [HDMI control] turned on)
If your source doesn't know about the receiver it doesn't know which order to control these devices, it will prioritize your TV!
I hope this helps. Basically, your source device (PS, Roku, Cable Box, etc.) needs to be configured to know HDMI locations.
Amzon TV -> AV Receiver -> TV
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