A couple of thoughts:
 
On the Windows audio routing, make sure that the default recording device isn't AES Record 01+02, in case Sonar thinks that you're recording there and won't playback there. Other DAWs may not care. 
 
Is the AES the only ASIO device? I ask this because it's not clear to me how Sonar decides which ASIO to use if there is a choice. I have a HILO USB, so there are USB ASIO devices as well as the ASIO AES16 devices. Reaper gives me a choice which of these I would like to use. Sonar seems to prefer the AES16 device. So Sonar might have output logic that wants to use the other ASIO device, assuming it's connected. Or something - just fishing here. 
 
Does the Lynx Demo app play to AES1+2? If that also works that seems to narrow it down to Sonar. 

PhilW
 
Does the Lynx Demo app play to AES1+2? If that also works that seems to narrow it down to Sonar. 

Thank you all for your feedback and suggestions. I think I have forgot to mention that I have used the Lynx AES16/Aurora combination since I bought it for about 11 years ago, and it has been working perfectly normal all the time (with all version of SONAR) up until last autumn sometime (not sure exactly when). During the time SONAR was "dead" I bought Studio One 3, and I also owned Pro Tools (use PT most of the time) And as mention above here, it works perfectly normal in those programs.
I think that one of the many updates that came with Windows 10 has changed something, and SONAR is now not able to take "fully control" of the audio device. I have used the same settings in Windows Sound setting all the time.