The link from Arc to surrounds is by a dedicated 5Ghz link the Arc creates. Is your Arc on wifi, connected by Ethernet cable? 

Is your wifi set to a specific channel - ideally, channel 1, 6 or 11 - or to Auto? 

Some issues are created by duplicate ip addresses. It’s worth setting fixed ip addresses for your Sonos devices - if you’re not sure, tell us router make and model and someone may be able to guide you. 

Thank you for replying.

 My Arc is connected to the WiFi and in terms of channels I have no idea. Today I turned my hub box off and back on and the speakers all reconnected. 
 

I am sure the issues you have highlighted above are at play. It seems crazy to me that this causes issues as I am sure I am not alone in having no clue how to resolve this until I either google or YouTube it. I feel with it being such a premium product it should JUST work. 
 

My hubbox is BT if there are any quick fix’s. 
 

Again thank you. 

Hi @Asmith88, welcome to the Sonos Community!

I’m sorry to hear that you’re having issues with your system staying connected. There are some issues with BT’s Complete WiFi (the black box and black disc) and Sonos which can cause association failures. As the steps and adjustments are different for each one, do you know exactly what BT router or setup you have? If you have any additional networking devices, like powerline adaptors or access points, those would be helpful to know as well.

Since rebooting your router generally fixes the issue, if you temporarily wire the Arc via Ethernet, does this prevent the system from dropping out? If so, and your network does meet our system requirements, then it may just be network settings (or something causing interference) that need adjusting.

If you’re not sure on how to change or adjust your router settings, I would recommend contacting our support team as they have the necessary tools available to make those for you and help troubleshoot this issue further.

I hope this helps!