I just got a 5700 XT and I am having no luck running Windows Mixed Reality. I have done a clean install on the most up to date drivers and I have also tried bypassing the WMR hardware compatibility test. I always get an "error code 14-2". Any help would be appreciated.
This is the answer from Microsoft Forum concerning your WMR Error: Windows Mixed Reality error 14-2 when Dell Visor plugged into Inspiron - Microsoft Community
Most likely it is a AMD Driver issue. I would open a AMD Support ticket to let them know if the above suggestions doesn't work from here: Online Service Request | AMD
EDIT: Also make sure your VR Headset has the latest Driver installed and Windows it completely updated via Windows Update.