Have you checked out this post: VR Welcome Guide!?
Particularly the known issues where it talks about having to modify registry for oculus rift.
I have the same headset as you and it is absolutely possible to get VR to run with this headset…but that registry setting must be changed.
Hope you get it sorted. (You can ignore everything to do with OpenXR for WMR and downloads from the MS Store- Windows Mixed reality stuff has no affect on Oculus headset and are not needed for your enjoyment of VR with your Rift)