Could be any, I suspect, of many things, the problem really is in knowing which one, and if you have any control over it. If it requires a check with a Sonos server before showing that data now (and I have no idea if it does), it might be that the Sonos server was unreachable for that hour. Unlikely for that to occur, I’d hope, but that calls in a bunch of other ‘connection to the internet’ issues, such as DNS issues (or even changes, that take time to propagate). Had you submitted a system diagnostic within 10 minutes of experiencing this problem, and called Sonos Support to discuss it, there’d likely be more concrete evidence as to whether the issue was internal to Sonos, internal to your mesh, or external to the internet. But I suspect that data has been erased from your system at this point, although I’m pleased you were successful in your ultimate goal.

Two things I try to be mindful of are the wifi interference FAQ (with the knowledge that interference isn’t only from WiFi devices) and setting reserved IPs for my network devices, where I can. Those two things have helped my system stay fairly ribust over the years.

Although there were two situations with interference that shocked me, one with an ‘older’ microwave which was leaking RF enough to cause issues with my kitchen speakers, and a ‘new’ neighbor, who installed a strong WiFi device on broadcasting on the same channel I was using in a location in their home close enough to disrupt my system. Once I figured it out (took a day or two to do so), changing my channel in use was relatively easy…it was knowing the issue that was hard. 

In the future, if you’re experiencing issues, I’d encourage you to run a diagnostic, and contact Sonos. Once prompted, thry’ll look at the diagnostic, and hopefully see some indication of what you’re experiencing, and why.