Are any of these other 50 products Sonos? It sounds, based on your post, that the Move 2 is registered to your second account, and showing up as ‘not registered’ when your controller is connected to your first account. At least, that’s a hypothesis, as I can’t connect a lot of the rest of your post in a logical manner.
Assuming you do have other Sonos device, were I you, I’d try a factory reset of the device. Then, I’d connect to them first, assuming it is S2, and use the ‘add a product’ function in the controller. But if you don’t have other Sonos devices, a factory reset will erase all data on the Move 2, from account data to playlists, to error codes that Sonos could use to help you. The Move 2 is a device that will only connect with S2, and not be seen by any S1 devices.
Unfortunately, we don’t know if any of these other 50 devices are indeed Sonos, I’m inferring that from your statement about first and second accounts. We also don’t know anything about their connection to the LAN, or for that matter, the network itself, including specifics about your router. Or, as I’ve pointed out above, which Sonos OS you’re using, or what device and OS it uses.
Essentially, in order to help you more effectively, we’ll need a lot more specifics. Or you could call Sonos Support directly to discuss it.
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 network and Sonos system.
Dear Airgetlam, the other 50 products are general items from phones, tablets, to smart home stuff.
The Sonos gear that I do have is a Beam soundbar and a Sub, both connected via UTP-cable, both S2.
I have logged into the Sonos S2 app via both my accounts, it did not make a difference to the status of the Move 2.
The funny thing is, it says “Not registered” with a “Resolve” button. When I click that it says “Move 2 has been added to your system and can now be used” with a chime from the Move 2. But it keeps saying “Not registered”.
Then I’d definitely call Sonos Support.
