Hard to tell from your post, but this may be a potential IP address issue, exposed when Sonos reboots their system every time they update their software. Try this:

Unplug all your Sonos devices from power. While they are powered off, reboot your router. Give the router a couple of minutes to come back up, then plug in your Sonos devices.

A more permanent version of this is to go into your routers software and assign reserved IP addresses for all your Sonos…if that is possible (it isn’t always a feature you can access, check your router’s manual). 

Note that this has nothing to do with signal strength of your network, it is merely an addressing issue, making sure the packets of data are being sent consistently to the correct device. 

Thank you