Hey @Werner_Hintze,
Thanks for checking back in on this long-standing issue. While I unfortunately don’t have an update to share, our team has tried and failed to reproduce the issue in-house, but we still have a development ticket in and are still attempting to reproduce it.
A few things to confirm in the meantime:
- Does this still only happen on sonos endpoints?
- From your last thread, there was a discussion around multiple active subnets within your local network. This still appears to be the case - were you ever able to test out temporarily disabling one of them?
This network segmentation is likely the root cause of the connectivity issues. Since Roon requires all endpoints and control devices to be on the same Layer 2 network, resolving this will involve adjusting your network topology to ensure all devices communicate within a unified subnet.
Let me know, and thank you! 
- The problem occurs with Sonos devices. Since I don’t have any others, I can’t comment on other devices.
- I still don’t know anything about other subnets. I have a FRITZ!Box as a router, which provides the Wi-Fi, and a second FRITZ!Box as an amplifier in the living room, which has a wall that is too thick for any other solution. This box is connected to the first one via Ethernet.
That’s all I know.
Yes, I did. I admit that I was just guessing whether that was the right setting. You don’t really have any other choice, because the help files and other documents usually assume that you already know the answer you are asking for, so a useful explanation is not necessary. But reading the menu entries led me to believe that this was the right setting.
I’ve not used this feature of a Fritz!Box, but because the Support Team raised the possibility of your having subnets, I would check to make sure that you just have one DHCP server running in the network, i.e. the DHCP in your router Fritz!Box.
Is there some reason why you are using a second Fritz!Box rather than a simple unmanaged switch in its place?
There is a DHCP server in the router. Of course.
I use this FRITZ!Box because I have it here. And I need a second Wi-Fi source, otherwise I won’t have any internet in the living room or on the balcony.
Yes, there is a DHCP server, but it seems to me that it should not be active - there should only be one DHCP server per subnet active in a home network…
Where can I see that? And when? A few hours ago, I disconnected the second FRITZ!Box from the network to see if, and if so, how well it works without it. So if a second DHCP server is active on the network, it must be a ghost. (Incidentally, I’m also pretty sure that the second FRITZ!Box didn’t have DHCP enabled. However, I can’t check that right now because it’s difficult (and currently impossible) for me to access the sockets and Ethernet cables.
Yes. It is set as Mesh Repeater.
I forgot tthe question about the DHCP server: The answer is no. No DHCP server is enabled in the second FRITZ!Box. (This means that definitely no second DHCP server can be active in the network..)
And by the way: I have quite a few devices running in this network configuration. Computers, telephones, printers, scanners, etc. Each with different software. All of these devices and software products have been running completely smoothly for a long time. Only Roon keeps causing problems (and has been doing so for a long time). Isn’t that strange?
Not really - the RAAT protocol demands a lot from a network - and WiFi networks in particular may not be able to deliver.
I see. I understand. Everything is in perfect order, and if not, that’s perfectly fine too. I’ll keep that in mind.
Hello @Werner_Hintze
I just checked the recent diagnostic data, and I do not see the same traces in the logs described in the initial thread.
Can you please reproduce the issue once more and note the time at which the error occurs. Then respond here with that time, and I’ll make sure we review the diagnostics related to that timestamp.
It happened just now: october 29, 07:58 (german time)
And just now once more: 8:09
And again.
And again (9:05)
And again (9:14). I stop this now and switch to the sonos app. It is ugly and I don’t like it, But it works. (And I don’t have to pay for it…)
By the way: It depends not on the file. If I play the same files once more it may work as expected or not.
It’s amazing. Isn’t it?
But one more thing is to funny. I must bring it here: Every now and then it happens that I play an album in Roon and can’t stop it because the Roon app shows me that nothing is playing, which is completely at odds with what my ears are telling me. The Sonos app also shows that Roon is playing something, but Roon doesn’t know it. It’s really great how Roon makes sure things never get boring.
Hi @Werner_Hintze,
Diagnostic logs show RoonServer failing to receive expected UPnP event responses from the Sonos devices.
This causes the device subscription to expire (the Zone tears down) even during playback.
The UPnP/GENA event handling that underpins Roon/Sonos connectivity can be a little sensitive on mesh networks. Usually, we recommend users enable multicast forwarding, but the Fritz!Box does not expose multicast features in the user interface.
I recommend you instead toggle band steering off and see if this makes any difference:
Please let us know if this helps. Thank you!
I can’t say whether that helps, because I don’t know what “toggle band steering” means or how to do it. I can’t find any information about it on the linked page.
I found a page where I read that I can disable band steering by turning on automatic channel selection. I did that, but it didn’t make any difference. Furthermore, when changing tracks, the beginning is skipped. The app also often displays something completely different from what is currently playing, etc. In a word: it’s the same mess.
Now the question is, what should I do: purchase another router? (Not possible, because I need the DECT function of the FRITZ!Box and don’t want to give up making phone calls because of Roon.) Move to another house that is Roon-compatible? Convert this flat to be Roon-compatible? Look for other software that does what it promises and what I’m paying for? (What would that be, apart from the horribly confusing Sonos app?) Or is there any chance that this problem can be fixed?
I tried this: To see if it might work better with a different router, I got a Deco BE 3500. After connecting it and connecting and updating the network for Sonos several times, I now only see one of my devices in Roon. What can I do to make the others visible too? Or have I now completely messed things up and will only be able to play my piano when I want to habe music?