Hi @JAJ68 

Welcome to the Sonos Community! And, apologies for the delay.

Could you please provide a screenshot of this behaviour, just so we know exactly what we’re dealing with here?

Please also submit a support diagnostic from the same device and reply here with the number given. Thank you.

The support diagnostic number is 903825440

Generally the Sonos playlists I have created will not appear even when closing and re-opening the app, only occasionally do they appear so that I can select them to be played

@JAJ68,
What do you see available in your ‘edit’ area of the My Sonos Tab…?

The iOS Sonos app has been reported as doing this for a while. Try SonoPhone from the app store instead.

Hi @JAJ68 

Thanks for the diagnostics.

Given that the Sonos app will only show you what the Sonos system at large tells it to, I think the app is having trouble communicating with the system - this is probably due to the multicast flooding I see at the Boost. Essentially, network data packets that are not intended to reach any Sonos devices are being sent to the Boost in error.

Please reboot your router by removing power for at least 30 seconds - this can sometimes clear up this problem. If it doesn’t, I recommend that you examine your router’s settings for IGMP Snooping/Filtering and enable it. If you have no such settings available, you may need to insert a IGMP network switch (around £30) between the router and the Boost (and other wired devices on your network). If it doesn’t help, you can always return it for a refund.

In addition, there is some interference near the Boost - please keep it at least 1m away from the router or any other WiFi devices.

I hope this helps.

I’ve installed the Sonophone app which is able to show me the Sonos playlists every time without fail (even with the multicast flooding) - this suggests to me that the problem lies in the Sonos controller app rather than my network (admittedly there are things I could do to improve the network traffic but I shouldn’t need to invest in additional hardware to work around a software deficiency)

Hi @JAJ68 

You are correct - you shouldn’t need to spend money. The best thing to do would be to find the source of the multicast flooding on your network and tell it to stop.

I’m glad to hear you have found an alternate solution - I can only presume the Sonophone app is holding on to information more and would therefore be more likely to show entries that have been removed by another controller, past the point at which they were deleted. Not ideal.

To be clear, nothing is being, or ever has been, deleted. The Sonos controller app OCCASIONALLY manages to show me my Sonos playlists but mostly doesn’t show them while the Sonophone app shows them consistently. This is why I’m convinced the problem lies in the Sonos controller app rather than my network

Hi @JAJ68 

It was a hypothetical - I was just pointing out that there is a reason for the app to not show playlists that the speakers are no longer providing information on (despite them trying). I think the Sonos app is simply reacting quicker to the momentary loss of data than the Sonophone app. Knowing nothing about that app, it’s an educated guess, but a guess nonetheless.

Multicast flooding is a problem for your whole network - not just for Sonos. You may need to get a packet sniffer app to figure out the source, but it’s something I highly recommend you address.

Please also note that buying a IGMP-capable switch was the third suggestion for resolving the problem that I gave you, and finding the source of the flooding is a fourth. You didn’t report that rebooting the router didn’t fix the problem, nor that you don’t have IGMP filtering as an option in your router’s configuration, so I have to assume that you haven’t tried either. If you resolve the problems on your network, I have no doubt that the Sonos app will operate as intended. 

I hope this helps.

It is a bug in the iOS app, and someone from Sonos on here did admit it a while ago. As per my suggestion SonoPhone works fine for you, as do my own Sonos apps. I have no idea how “multicast flooding” could affect a simple UPnP call.