Hi @brubru51 

Welcome to the Sonos Community, and thanks for sharing!

Appreciate this workaround, but there should be a simpler solution. And the issue is not getting sound from both devices, it is shutting off the sound from the Arc—a critical need if the Arc is in a bedroom occupied by two people, one of whom is sleeping.

When connected to a smart TV through the eArc and HDMI connection, the Arc prevents prevents a user from using a Bluetooth wireless headset or earbuds. This is because the HDMI connection is an always on connection, the Arc will not release the signal even when the audio output in the TV is manually changed to Bluetooth. You can try this in your TV settings and it will work for a second, but then the HDMI connection re-establishes. Basically, with the Arc installed using the HDMI connection, you lose the ability to watch TV through a wireless headset. So much for watching TV after the spouse goes to sleep.

The solution cannot be to downgrade to optical, or manually unplug the HDMI cable that is likely buried in a cabinet or removing the Sonos components when using headphones and then reinstalling them each time after.

The solution for this is to be able to turn the Arc off. I am not asking for an on off switch on the device itself, though that would not be a bad idea, however, not particularly useful to current Arc owners, but Sonos should build into the Sonos App a toggle switch to disable or disconnect the Arc temporarily when the user wants to use headphones; just like you can turn Alexa on or off or any other software with a software based toggle. 

This is not an insignificant problem and violates the what has always been the guiding principal of any audio purchase—it has to pass the spouse or partner test in the categories of size, visibility, and ease of use. The Arc fails the third and key test.  
 

@JTM670 Have you tried disabling CEC on your TV when you want to use headphones?