The build checks if you have a connected VR headset and will launch in VR mode if so. Maybe that's what you're seeing.
I know it launches to VR, but it's not really ready yet, so if that's the case you can fix it by closing SteamVR or Meta's Desktop App so it doesn't think a VR headset is the way to go.
Or toss on your HMD and see if video is streaming through while the game is running.
Hopefully that helps.