Several concerns here. First, I’ve not seen any other posts about this that I can recall, so ‘a lot of people’ seems perhaps disingenuous. Second, please don’t factory reset a device without talking to Sonos first. In 99% of cases, it doesn’t fix the problem, and ends up erasing any data from your device that could be used to assist you. 

In your case, 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.

I have exactly the same problem, and its wearing me down, 

What did Sonos say, when you followed my suggestion above, and submitted a diagnostic and called them?