Hi there @Christian Roebaek.
Thanks for reaching out and welcome to the community! Let me help you figure this out.
Is this happening on a single controller? Have you tried using a different device/controller to see if it’s the same?
I would like to know the router’s make and model to check if we have a known issue with it.
If you have extenders or any networking devices, please indicate them too. How are they connected (wired or wireless)?
To check some data from your system, please send in a diagnostic report through the Sonos app using the affected device and reply with the confirmation number. I'd start by reviewing your system and see if there’s anything causing this issue.
Looking forward to hearing from you soon.
Hello again
I have tried installing the sonos app on another phone but with the same results.
My router is an Icotera i4850 (the same model I used before changing supplier)
I have no network extenders. I have a PS4 and an Apple TV connected by wifi.
I have tried to start over, beginning with the Play:3, but no luck.
Then I started over again, now beginning with one the of Play:1 speakers. This time I actually succeeded and was able to connect to the wifi.
I then added the next Play:1 and finally the Play:3.
Unfortunately the sonos app still looses connection all the time.
To reconnect I have to be close to the first Play:1 speaker I added. If I am closer to one of the other speakers, I loose connection again.
I have run the diagnostics. The number is: 1424438112
Br. Christian
If you use IPhone/IPad as controller try this:
Switch off wifi assist https://support.apple.com/en-us/HT205296
Also, switching off private address may help https://support.apple.com/en-gb/HT211227
Hello ClausN
Ty for your suggestions. Unfortunately they did not help.
BUT.. based on the notion that the problem could be with the iPhone, I tried installing the Sonos app on an android smartphone and here it works flawlessly! No connection issues.
My smartphone is an iPhone XS running iOS version 14.3
The problem is very consistant. I have to be closest to “speaker 1” to connect. If I move towards one of the other speakers, I loose connection and have to go back to speaker 1 again.
Any ideas?
The Sonos app/phone does not connect directly to a speaker - it connects to the router which then connects to a speaker, by cable or by wifi. Thus the connection does not depend on how close you are to one of the speakers, but rather how close you are to the router; switching off “wifi assist” could have been a possible solution to that but obviously was not.
I’m quite convinced the resolution is to be found in the connection between the IPhone and the router.
You can try to deactivate 5 GHz wifi in the router and have it running 2,4 GHz b/g mode only, just for testing; some routers have difficulties bridging between 2,4 GHz (which the speakers connect to when they are in wireless mode) and 5 GHz (which your IPhone may have connected to), although I doubt that will help as your Android connects fine, but the router reset most likely made by your new internet supplier may have caused some disturbances.
Paying attention to this article about wifi interference may prove to be usefull.
Hopefully @Annazel S will soon be looking into your diagnostic.
It sounds logical that the connection should be between the router and the iPhone but strangely enough once I loose connection I cannot reconnect even if I am standing litteraly next to the router.
The router is located in the middle of my livingroom. The speakers are at opposite ends of the room. Again, I connect at speaker 1. Then pass the router and move towards speaker 2 and loose connection. Only once I am back at speaker 1 can I reconnect..
(dont ask I gave up on understanding network tech years ago 
)
But going on and following your 5GHz/2.4 GHz idea, I noticed that the android phone was running 2.4 GHz on the router. I deactivated the 5GHz band and the iPhone jumped to the 2.4 and now I do not loose connection no matter where I am in the livingroom. A huge improvement. Thank you very much!!
That being said… if I close down the app on the iPhone and start it up again I cannot connect unless I am standing next to speaker 1.
(the android is fine)
I have no explanation for the missing connection after closing the app.
Have you tried a system refresh? Power off all Sonos speakers, restart the router and wait until it has fully restarted, then power on the Sonos speakers, and restart your iPhone (probably makes no difference as the Android works fine, but worth a try).
After this and while the connection works, send in another diagnostic, post the number and hope for Sonos to pick it up - or call Sonos Support to discuss the diagnostic https://support.sonos.com/s/?language=da (scroll to the bottom for phone number and office hours).
If Sonos Support manages to resolve the issue, please post the answer here to help other users with similar problems.
If you want to reactivate 5 GHz give it a name different from the 2,4 GHz, if your internet supplier/router permits. That way you can connect your iPhone to 2,4 GHz and still have other devices like Apple TV on 5 GHz, if you prefer that.
Hello again
I have now tested for some time after having forced my iPhone to use the 2,4 GHz band.
While I do loose connection once i a while I am able to reconnect again immediately which i a huge improvement. I do not doubt that the 5GHz vs 2,4 GHz issues was the culprit.
Thank you very much for your help.
