Since the Sonos Five is hardwired to your router, the BOOST is not doing anything. The natural assumption here is some sort of network interruption of the data traveling to your Five. It could be the source having issues, it could be your own network, particularly a potential duplicate IP address issue, but there just isn’t enough information to be certain. 

I would start with a simple network refresh, by unplugging the Five from power, and rebooting your router. Once the router comes back up, plug back in the Five, and see if the issue is gone. If it still happens, I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your Sonos system and network.

Not necessarily. It depends on the physical disposition of the wired and wireless devices. 

For example I have two Ports wired, one on either side of my office. Each supports a different set of wireless devices.