I’ve had my Sonos set up for about a week now. I’ve watched numerous videos showing how to connect the speakers to my WiFi and how to use the app. 
Recently, I had Definitive Technology surround sound speakers with the Onkyo recover and app. Debated for awhile and made the move to Sonos. 
What a difference! However, those of you who had issues connecting (bridge mode, powering down speakers and getting frustrated, checking router, app not connecting), yes I’ve been there with these issues all week until now. 
 

I currently have our cable router and we bought the AMPLIFI mesh WiFi unit. When our house was built, they installed all of the wiring in our downstairs closet. I never knew why they did that but I hated it. Although, I’m no expert at all of this so we kept it there. 
When I installed the Sonos, It would drop my connection from the app all the time. My wife knew I was going to go crazy after disconnecting my old unit with issues and now I can’t get this work properly. 
I called Sonos and they stated to contact my internet provider and they needed to put my router in bridge mode. Now I’m calling TDS. 

I speak to Tds and they were nice and I got into our routers setting and changed it to what the Sonos rep stated. Was it right, yes…… but, the next day we didn’t have internet. They cut off the WiFi since I had the AMPLIFI mesh system but I still had internet but the next day I had no internet. 
Now I’m calling TDS back because my wife works from home and she had a big Zoom meeting that she had to be on. 
Im on the phone with TDS and they had to bring a tech out to see what was wrong. The tech was super nice and when he saw what I had, he simply asked, how many cable boxes do you own? I said 3. He asked, how many are hard wired and how many are wireless? I said 2 are hard wired and 1 is wireless. He laughed and said, sir… your wired cable boxes speaks to the wireless box with our device. Without WiFi on the box, the router can’t speak to the wireless box. Hmm….ok I said. So then he tells me, here is what we need to do, and for those out there struggling to get it to work, here is what he did for my individual set up:

He did a factory reset on the router.  Got it back to like we had it before. Then I restarted the mesh system, then each individual speaker, and it was back up.  Hmmmm.. but I told him that my app is going to disconnect again. He mentioned to me that my mesh system needed to be disconnected from the router and moved upstairs to give our house an “umbrella “ WiFi signal around our house. We had an extra Ethernet plug upstairs landing and he placed it there. 
 Guys…. When I tell you we haven’t lost any signal or dropped Sonos app, it works! My wife and are able to use the app faster than ever. She likes watching YouTube videos and she’s able to do that with the app that’s installed on my phone and is shared since she’s in the house.
My AMPLIFI app says that the system is in 2.4ghz and everything else is 5ghz.  So not saying the bridge mode doesn’t work, but for my individual set up, I couldn’t do that. I’m sure someone will tell me that I could have done this or that, but I’m not touching anything with it because it sounds amazing and the app works flawlessly!