Skype room system cant sign in

Hi! 

I have a problem logging on to Skype for Business on-premise with 2 different Skype room systems.

Both are on version 4.0.64.0 and I am seeing this error message: we can't sign you in because the server couldn't be reached or the server version is incompatible

The customer has username@domain1.no as the SIP address and has domain2.no locally. I have put both domains in the configuration page on the SRS. I have also tried the registry fix HKLM\Software\Microsoft\SkypeRoomSystem Trustedmodeldata = "all domains configured"

I have tried to connect one of the SRS through internet, then it authenticates with the edge server, same problem.

Is there anybody that has a solution for this?

PS: I know they work, tried to connect to another Skype for Business org and it works. Also work onOffice 365.

Similar thread with no solution.. https://techcommunity.microsoft.com/t5/Skype-for-Business-IT-Pro/Trouble-logging-into-SfB-w-Logitech-SmartDock/td-p/96628