I was having the same issue where I would set-up the flight before hitting the control tab key to enable VR. Once I enabled, I’d go from the WMR screen, to a screen that looked like exploding diamonds and it would loop back and forth. Someone on the forum mentioned that the reason for the loop was due to the software opening up the ATC and Camera displays onto a second monitor. If you close out the ATC and Camera displays, enable WMR, it might work and connect VR to the sim without the loop. I actually have a triple monitor set-up that I used with X-Plane 11 but with MSFS I use one for MSFS, one for Pilot 2 ATC and the third for checking metar settings when setting up an IFR flight.