Hey @Frankey1cro ,
do you have the v2 cable? Because there should be a button on the box where the HDMI cable for your HMD comes out. Press and hold that button until the white light on the box switched off. This is also disconnecting the HMD.
But to your problem: If you start WMR are there multiple displays in the display settings? If yes, you might have Preallocate virtual monitors enabled.
Do deactivate it follow this thread: