No audio through television speakers

[Citizen Cook]

I have a 1080p BenQ monitor and a 4k Samsung TV connected to my GPU. (1080Ti)
I'm outputting on both screens simultaneously. Last night I plugged in my headphones and today after removing them I can't get sound to output through my television speakers.
I went into playback settings and made the TV my default and can see the green bars flicker suggesting that the PC is outputting the sound. If i make my desktop speakers the default playback device then i can hear the audio just fine, but not when I make the TV speakers the default.
I suspect the HDMI 2.0 cable to possibly be at fault but cannot test this theory because i only have the one. It's only 6 months old however and the loss of sound in conjunction with the use of headphones makes me suspect it's a Windows 10 issue of some kind.
I've checked the audio, GPU, and OS drivers and all are up to date...

I'm at a loss.

 

[Citizen Cook]

I have no idea why, but when i turned on my PC today the sound was working again. Any idea why that would be?
What just happened?

 

[Rocky Bennett]

HDMI handshake;

https://support.channelmaster.com/hc/en-us/articles/200377955-Why-does-my-HDMI-connection-not-seem-to-work-all-the-time-or-why-is-it-intermittent-

 

[Citizen Cook]

HDMI handshake;

https://support.channelmaster.com/hc/en-us/articles/200377955-Why-does-my-HDMI-connection-not-seem-to-work-all-the-time-or-why-is-it-intermittent-

Ah yes, the anti piracy tech that doesn't prevent pirates from doing their thing but does cause endless headaches to honest paying consumers.

 

[Rocky Bennett]

HDMI handshake;

https://support.channelmaster.com/hc/en-us/articles/200377955-Why-does-my-HDMI-connection-not-seem-to-work-all-the-time-or-why-is-it-intermittent-

Ah yes, the anti piracy tech that doesn't prevent pirates from doing their thing but does cause endless headaches to honest paying consumers.

Unfortunately you described this technology perfectly.