Why doesn't discord use the communication channel when it's set as default in windows??

This app is the ONLY app that does not respect the audio channels I set in windows. I have a Sennheiser headset. They split the communication audio and main audio source so that communication audio does not interfere with the 7.1 surround. 

However I can never hear anyone on this communication audio source even thought I have it set in discord as the output. From my research this has been a problem for a very long time. Fix it!