Sorry you’ve had so many network issues, especially on Sonos, which requires a clean network to operate on. 

Hi,

Thank you for the reply. Would you kindly let me know what does 'clean network' mean?

My household cannot be unusual in having many items that rely on wifi, as well the Devolo equipment.  How can Sonos equipment be adjusted to work with it all. Will the software update on 7th May resolve my problems?

We will all need to “wait and see” with respect to the May 7 event.

I have no experience with Devolo, but in general we discourage using networking over power line. Occasionally EoP (Ethernet over Powerline) has been a magic bullet, more often it has been a big pain. I don’t know which path Devolo will lead you down. Are any of your SONOS units wired to the network?

The way that Sonos interacts with a network is pretty much unlike the majority of devices. There is not only the need for the speakers to constantly maintain a connection with the internet, but also a constant connection between themselves, and if you have your controller device open, a constant connection with that device. Most other devices just need a single connection, be it to the internet, or at the most to a single other device.

This make Sonos a bit more ‘sensitive’, as network devices go, to various forms of network problems, which can be caused by a plethora of issues, including things like duplicate IP addresses, wifi interference , and other network issues. It isn’t impossible, by any stretch, for the Sonos to be at fault, but in the vast majority of cases I’ve seen over the last ten plus years, well over 99% have not been issues with the Sonos devices or Sonos software that runs them. Additionally, due to this complexity, Sonos has some particular requirements. There is a list of a very few routers that don’t handle the network properly, that Sonos maintains. As @buzz suggests, some (maybe all?) Devolo and other power line products are know to munge network addresses, for some reason I’m not familiar with, or even break up segments into different subnets, which means the Sonos devices can’t talk to each other, the controller, or the internet properly. 
 

Sonos does maintain a Sonos Network Requirements FAQ, which briefly mentions Ethernet over power line devices, amongst other things that will cause issues. 

Just to add to the first post; I have had Sonos for about ten years. I have always had Virgin wifi, and have always had problems with Sonos. If I ever want to listen to music, I have to decide “do I want to listen so much that I am prepared to go through with the hassle and jeopardy of connecting?” If I cant face the potential disappointment, I leave it. I think Sonos has programmed me (Pavlov dog style) to now dislike music. Thanks Sonos. Really.  I have recently been given a hub 4 by virgin, and Sonos refuses to work at all. I have contacted Sonos and they couldn't fix it - other than to say I had to wire it up. This isn't great for a wireless speaker, and frankly should justify a claim for my money back on that alone. Apart from needing to howl into the wind, the purpose of this post is to say it never dawned on me hat Sonos and Virgin don’t like each other and this is the cause of the problem i have had for ten years. And having seen the first post and others in the community I am sure of this.  I made this point on another thread, and someone seemed to think this was my fault, or ask why should I expect Sonos to have to be compatible with everything? He said if i am buying a Linux system then i should expect some maintenance. I find that a very silly argument. If Sonos isn't compatible and easily connectable to everything, they should make it very clear. If it isn't easy to use, and only the domain for experts , they should say so. If it isn't compatible with the UKS largest Wi-Fi company, they should say so. Their marketing does no such thing. If any one else out there with Virgin and also has connectively problem's wants to add to the below, please do. I wonder if there are enough examples out there to justify making a legal claim. I am a consumer lawyer, and know that any such claim would need evidence. so if you are like me, please add your experience. (I know everything is about the new app at the moment, but i think it is much worse - it is about ten years of unreliability)