SonosNet is a 2.4GHz mesh. 

Home theatre satellites (surrounds, subs) connect to the master player over a local 5GHz. 

When connecting to WiFi, in “wireless” mode, many of the devices can use 5GHz WiFi. See https://support.sonos.com/s/article/126

Note that HT master players can never connect to a 5GHz WiFi, as their 5GHz radio is dedicated to serving their satellites.

As for your WiFi scan results, the strongest signal -- Xbox-Server-*** -- is 40MHz wide, so will cause problems for just about anything not on ch 11. It’s sufficiently strong that it’s likely to come from your own property.

On the other hand there are signals on ch 8, which overlaps onto 6 and 11 making life difficult for those ones.

Yep Xbox-Server is ours. Odly when the Move is on the landing next to it it plays fine. 

When moved into the bedroom it loses connection, I believe next doors router is close by.

Apart from my 5.1 system can I stipulate the rest use the 5ghz channels instead or is it just pot luck?. 

The Playbar is within a meter of our router so no issues with that on 2.4ghz.

This is 5ghz 

I’d recommend you start by confining Xbox-Server to 20MHz width, centred on ch 1, 6 or 11, so it can better co-exist with other users of the band.

In WiFi mode one can’t steer a Sonos device onto a specific band. However as I understand it devices will attempt to connect to 5GHz if they can, subject to the prevailing RF conditions.

Thanks, my daughter has a Play:1 on S2 I might have a look at how it's connecting to our router.

Shame you cannot lock on just 5ghz as that would be a good solution for me.

Will see what I can do with the Xbox-Server but that has been going for a long time. 

Saying that we've been on 2.4gh Channel 6 for ages ans seems like someone has muscled in with a stronger router!.

The Arlo follows our main router channel eventually (it's programmed like that for some reason, less interference they say..).

Would S2 on SonosNet (wired through my Playbar) allow me to add a 5Ghz only SSID?.

Was going to try SonosNet but it seems the Move will not connect to that at all?.

Could I wire S1 in SonosNet, turn off my 2.4ghz channel them add the 5ghz to my Move? (Sonos list the Move as 5ghz compatible on S1?.).

Yes, and the same goes for S1. SonosNet is entirely separate from WiFi. 

I have precisely this arrangement: SonosNet, plus a dedicated 5GHz SSID for the portable players.

Move cannot connect to SonosNet. Move needs WiFi.

Yes, as noted above.

Also bear in mind that 5GHz has less range than 2.4 generally.

Thanks for the replies!.

I will try SonosNet, take my 2.4ghz details off all the speakers then try and get the Move on 5ghz (May need to factory reset it and add back in while the 2.4gh is turned off?).

I have good enough 5g where the Move lives, will see how it fairs outside in the back garden/ workshop but will cross that bridge later.

Hopefully have a better system by the end of it.

Got there in the end!.

Getting my Household on SonosNet was easy as pie, just plugged it into my router and nigh on instantly all my speakers were on WM:0 (bar the Move).

Next was trying to eradicate my 2.4ghz credentials, with the Move powered on obviously I couldn't remove it. Powered Move down, removed the 2.4ghz entry but as soon as I turned Move back on it connected back to 2.4.

I tried adding my 5ghz though the S1 app in Network Setup, but it would only show 2.4ghz SSID's and manual entry didn't work (incorrect password shown).

So my resolution was to Factory Reset the Move, and within that process it saw my 5ghz SSID and connected straight up.

All working great so far!.

Sorry for long winded post but it may help others out.

Working a treat now, no dropouts at all!.

I left SonosNet on the "dirty" channel 6 just to see what woukd happen and it's been amazingly stable.

Might try a Powerline 5ghz extender in the workshop an see if the Move will connect to that .

Saying that I have good 5ghz signal down the garden (30meters or more from router), which is surprising!.

Sonos of course doesn’t officially support EoP/powerline connections. Their bandwidth/latency can vary hugely, depending on the condition and path of the electrical wiring, mains-borne interference, and what’s plugged in nearby. (The old Bridge power supply was great at destroying the EoP RF carrier locally.)

That said, when they work they can certainly assist with Sonos. Just make sure you don’t end up with one of the makes which blocks certain types of traffic that Sonos depends upon. 

I have a TP-Link, we use one for the kids Xboxes and it seems very stable.

The spare TP-Link can go in the workshop for testing, not the end of the world if it doesn't work as it's it's just sat around doing nothing!.

Was looking into Mesh networks but I don't think I need to go down that route now. 

IIRC TP-Link powerline should be okay.

Mesh WiFi and Sonos (in ’wireless’/WiFi mode) don’t always get along. The standard suggestion from Tech Support then appears to be … to use SonosNet.

If you have a working solution then I’d recommend you stick with it. 

I think this is as good as I'm going to get it, put the kids Xboxes on 5ghz, Sonos on SonosNet (ch11 for now). Arlo always follows my router channel (how it's programed). I'm VM and Arlo on these.