Just as another suggestion for you to ponder, why don’t you wire a Sonos Boost to your router instead? - this document link below explains the difference of wiring a single Sonos product and creating a wireless ‘mesh’ system instead for your speakers and perhaps improve their connectivity back to your router:

https://support.sonos.com/s/article/3235

The OP wants to wire more than one device, Boost or no Boost. 

@Nando010 You’ve obviously ascertained that a loop is present, presumably because a broadcast storm is taking your network down. Can you kindly identify what’s currently on the path between the two wired Sonos components, in terms of switches (or indeed router)? 

As a matter of interest, does leaving the kitchen Play:5 wireless not work? If necessary it should act as a mesh relay into your garden room anyway, without needing to wire it. 

Yes my network comes to a stop when I plug in a second Sonos. Im trying to plug the play 5s to an unmanaged switch that is run to my Nighthawk rax200 by a 15 meter ethernet cable. Cable is fine.

looking into it more I have just noticed the problem could my main hub the Virgin Super Hub 3 is incompatible with Sonos and only one device can be connected.

You should find that things will be okay if you don’t wire Sonos across the router. In other words the whole Sonos system must link back through just one router port. Wire your Sonos devices to a switch, then wire the switch to the router.

Thank you. I will give it a go, just waiting for new ethernet cable.

Hey @Nando010,

Has your new Ethernet cable arrived yet? If so, how did you get on with ratty’s suggestion?

Yeah I have just spent the last couple of hours trying different ways to connect even connecting downstairs play fives and the upstairs beam both direct to my nighthawk it just kills the internet. I've tried everything even different switches and its just not having it. So im just gonna have only one plugged in.