My system takes a while to connect, then when I change volume or songs there can be a five second lag. Yesterday I had to unplug two speakers because I couldn’t them to turn off using the system. 
 

I have a complex system with nine speakers hooked up to two iPads and an iPhone. But the old system worked flawlessly. 

I’d suspect that there’s been a duplicate IP address issue that has cropped up during the most recent update to your system. Try unplugging all your Sonos devices from power, and while they are unplugged, reboot your router. Give the router a couple of minutes to reload, then plug back in your Sonos devices. 

An update on the update: A common problem noted on this site is missing playlists. I had noted that SOME of my playlists had appeared as a subcategory of Sonos Favorites. However, this happens only sporadically. Even when they show up, not all of my years-in the-making playlists appear. Clearly, this software was rolled out long before it was ready. Why?