The issues you are having could be caused by network interference. Sometimes an update from your ISP could cause issues like this.

Have you tried powering off everything: router/network, speakers and phone. Wait for five minutes. Starting with the router/network, power it on and allow it to fully boot.

Then starting with the Beam, power it on and allow it to fully boot.

Repeat for the rest of your speakers, then power on your phone and connect to the system.

Make sure there are no VPNs running when using Sonos. 

If you have extenders to extend your WIFi, you may want to look at a mesh system instead.

If you have powerline adapters, see above.

EDIT: Another troubleshooting step you can take is to power off the Play 3 and Play 1s to see if that helps. Sometimes mixing older hardware with newer hardware slows down the communication between speakers.

If that helps, you may want to consider hardwiring the older Play speakers. Thats what I have done with my Play 1s and I have no connection or streaming issues.

Yes I’ve tried all the reboot suggestions from all the various threads with no success, I’ve had the same router for over 2 years and nothing has changed?

we never had to be IT specialists to use Sonos, something is now fundamentally flawed with the system and it’s madness for the cost, it should just work like it used to?

I’ll give it one more go next weekend but after that I’m done, either all sold on eBay or in the bin, life is too short for this frustration of awful tech.

I’m shocked Sonos are allowed to get away with it, a quick google produces hundreds of result for people having issues, it’s disgusting for such a premium product in this day and age.