Hi hopefully you can help...

I've been having trouble using my Sonos system recently.

The Arc disappears from the Sonos system after playing music in a group with other speakers from Spotify.

When I group the Arc (with sub and 2 rear surrounds) with a Sonos One and Sonos Five,  it fairly consistently drops out of the system, requiring a power cycle to bring it back. 

All speakers are connected by WiFi. All except the Arc are using 5ghz, not sure if this is relevant...

My wifi router is an Asus RT-AX55. I had a search and found an article suggesting disabling a setting (airtime fairness),  but this doesn't appear in my router config.

I've tried connecting an Ethernet cable to the sub and use SonosNet but this didn't work at all. Nothing could connect, I assume its because it is part of the Arc subsystem…

Any ideas on how I can fix this for good?

Thanks,

Paul