@SuzB 
Are the speakers dropping out and simply not appearing in your Sonos App (a device-discovery issue by the App), or are they actually disconnecting from the wireless LAN and your main router?

Does the router show them as disconnecting and losing their IP address and if so what Status-LED light sequence do you see happening on the speakers, when they disconnect?

Besides the main WiFi router, do you have any other wireless access points/extenders or EoP devices, broadcasting/repeating the routers WiFi signal? 

What is the make/model of your router?

Which mobile controller device are you using and does that mobile have any security software running on the device, such as VPN client, firewall or anti-virus etc?

Hi Ken, first thank you for taking the time to respond.  Second, I’m an old lady with limited technology knowledge so please use the most basic language. And last, I figured out the problem.. I just don’t know how to fix it.  I have regular Wi-Fi and a google mesh which are separate networks, passwords, etc.  somehow,  the play one speakers got onto the google mesh network while the play 5 is on the regular Wi-Fi, therefore even though all speakers work, they just don’t work at the same time.  This only took an entire day for me to figure out.  
 

Problem now is how do I get them all back to one or the other?  I tried the reboot on the two play one speakers several times yesterday. However, without any prompt by me, they loaded BACK to the google mesh when I wanted them on the regular Wi-Fi.  Actually, I don’t care which network they all on as long as it’s the same for all.  Sorry if this is confusing, I just don’t know how else to explain it.  
thank you again for your time 

Note both the Sonos (mobile) controller and the speakers need to be on the same network and so I recommend you put all onto your Google mesh, as that’s likely where you are connecting your mobile device to (I presume?) ..aswell as the majority of your Sonos devices.

You really/ideally need to start by removing/forgetting the initial (ISP provided) routers WiFi network from your mobile device and switching off the WiFi adapters on your router too, which are not needed now that you are using the Google WiFi instead. You may need to check your router user-manual to perhaps change that setting as the settings are often different for each router brand, or model. I hope you, or a friend/family member, or colleague, can perhaps sort it.

You need to also see if you have both WiFi networks (Google and Router) stored in your Sonos App network settings. If you do then remove just the Routers WiFi SSID only - here’s a link to explain how to do that…

https://support.sonos.com/en-us/article/remove-a-wifi-network-from-your-sonos-system

If your Sonos Five is part of your existing Sonos Household, then on reboot it should connect back to the Google WiFi when you have completed the steps mentioned above. If however it’s become part of a separate Sonos Household then you will need to factory reset it (having completed the steps mentioned) and then add it back to your original Sonos setup as a new device.

The instructions to factory reset your device, if needed, are shown here in this link:

https://support.sonos.com/en-us/article/reset-your-sonos-product

I’m sorry I cannot make/explain things any easier, but if you’re struggling to resolve the issue then hopefully you can find someone to assist you, or perhaps call Sonos Support and see if they can assist you. Here is a link to call them…

https://support.sonos.com/s/contact