Get your Sonos and controller on the same Wifi and see if that helps.

 When you say “I split my router” does that mean you are now seeing a 2.4 SSID & a 5 SSID?  If so do they both have the same name and password?  Something like:

   Mynetwork 2.4

   Mynetwork 5

Can you describe your network? This will help members find a solution for you.

Do you have a managed switch in your network? If so, the Beam may be crashing your network if you do not have STP enabled.

Yes just so, and both have same password 

 When you say “connected TV to 2.4GhZ” do you mean you did this within the TV settings?  That would, of course, not have anything to do with the Beam 2 setup.  Are you saying the Beam 2 does not complete Sonos app setup because the Sonos app will not accept your password?  Is your mobile device with the Sonos app on it connected to 5GhZ?  Are any other Sonos devices showing on the Sonos app or is this your first Sonos purchase?  If you have other Sonos devices what band are they connected to.  The Beam 2 has to be connected to 2.4GhZ.

My mobile device and beam are on same 2.4ghz frequency 

Yes, all relevant devices are on same 2.4ghz. I get as far as the connect to WiFi phase and once I put password in it says cannot connect. Try multiple times then asked to connect to ethernet. When I do this the sound comes out of the beam 2 for a couple of seconds before silence again and either asked to reboot router (which I have multiple times) or stes cannot connect and try later before directed back to start. Do I have to have different passwords for each frequency as only the 2.4ghz one shows up once I separated them?

Thanks for your input guys. Sorted: VPN wasn't permanently locked out for app. Once locked out straight through.