Hello @m-m-i, welcome to the Sonos Community!
Thank you for bringing this in to our attention. I’ve brought it internally and we are currently investigating this issue, but have no ETA for a fix.
Could you please Submit Diagnostics and share the number on a private message with me?
I will reply on this thread when I get an update.
Thank you again and I hope this helps.
Thanks Sotiris have DMd you the diagnostics number.
Just bumping this. Never heard anything back.
@m-m-i
None of my speakers are ethernet connected but I can still change the SonosNet channel number. I suspect it’s the same for everyone.
I wouldn’t say it’s a bug as it has no detrimental effect on anything as far as I can tell - I’d imagine it only comes into effect once a speaker is ethernet connected, thus triggering SonosNet, and potentially remains off at all other times despite the function to change its channel.
Maybe the documentation you linked to just needs to be amended. Or the channel greyed out. But either way, no harm done in the meantime. (If someone can see a SonosNet signal being issued while all speakers are wifi connected then of course that’s an issue to be looked into as the system would be potentially causing its own 2.4ghz wifi interference.)
(If someone can see a SonosNet signal being issued while all speakers are wifi connected then of course that’s an issue to be looked into as the system would be potentially causing its own 2.4ghz wifi interference.)
Why? SonosNet and WiFi mode can exist in parallel.
Can they..? Once a speaker is connected by ethernet, the rest jump on SonosNet and off WiFi.
Or so I thought… Maybe my thinking is outdated now!
Can they..? Once a speaker is connected by ethernet, the rest jump on SonosNet and off WiFi.
Correct. What I meant was that SonosNet-capable and SonosNet-noncapable units can exist in parallel.
I for one favor my SonosNet setting. 
It’s usually best to use different channels for SonosNet and WiFi. The most modern SONOS units don’t use SonosNet. Therefore, there can be both WiFi and SonosNet traffic associated with the system.
@Rhonny see my original post, the documentation states:
“If all your Sonos products connect to your WiFi network, the SonosNet Channel will appear grayed-out in the Sonos app and cannot be changed.”
So I would say this is a bug as what the docs state is not what is happening.
Does it matter in any meaningful way to your use of your system? I’m not being obtuse, just interested why you are so determined to press on with resolution.
I don’t think this needs explaining, but I will humour you.
If the settings aren’t greyed out as documented it gives users the indication Sonosnet is active. Even if it isn’t technically active, this is a confusing user experience especially when it contradicts the docs.
Beyond that, the fact this is occurring points to an issue somewhere. This issue could be backend / account related, it could be caching, it could be frontend only. Investigating it potentially uncovers other down or upstream issues, and fixing it improves software quality and user experience.
This is my area of work, I am the product owner and design lead of a corporate design system and I manage the backlog of a dev team. In my company triaged bugs are high priority and not allowed to sit around.
