I had the same occur. Very irritating- It’s the new steamVR motion smoothing crap and AReprojection. I had to roll back to a old version and stop steam from updating which is stupid and unfun. You’ll note on the current steamVR - reprojection is now alway on - and they removed options - on my system it flutters all over the place where as a few weeks back I was running SS 2.1 You can turn reprojection entirely off - but not in the menus cause ... well .. cause they are having a laugh. Regardless, you can click on the hdm visor icon - select mirror and then hit shift and A - then you can start the game However - it now runs horrible. I was for the record running with it off before. But whatever they’ve done has mucked stuff up.