I have had issues with my system for a long time. 
Response from my phone has been crap at best. 
Sometimes it worked but was extremely slow often it did not work at all. 
I have a modern WiFi that gives me a connection that works for 2.4 GHz as well as for 5 Ghz. 
Sonos speakers use 2.4 and my phone use 5. 
Making a new net using only 2.4 and connecting my phone to it solved everything. 
I now have two nets. One for my computers and stuff that needs faster internet and another for the phones and Sonos. 
It is for sure a work around but it works.
Sonos should solve the issue since most modern routers works as mine. 
I hope I can help someone else with this post. Since I have been struggling whit this issue for years before this struck me as it might be the issue. 
 
