how to register a system on the application

Not sure I understand. When altering most stuff on my ‘account’, I go to the website www.sonos.com and do most things there. If I’m changing my speakers, I use my iOS controller app. 

Of course, there’s a lot more information visible on the website, but 99% of the time, I don’t need to refer to it, even though the ‘my system’ information is pretty interesting. 

But if you’re continuing to have issues, I’d call Sonos Support to discuss it.

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