I seem to be having a problem with having Smart Smoothing turned on in both Steam Home and HL:Alyx.
This only seems to be happening in my Windows 10 installation and not my Windows 8.1. Both have the same version of Steam, Steam VR, Pitool and both have the latest Nvidia drivers installed.
The problem is that on the left and right edges of the buttons of the games you have installed there is a sort of watery, wobbly distortion when you move your head around.
In HL:A It is noticeable in-game too. For instance if I go into the room at the beginning and pick up the lid from the tub or one of the whiteboard pens and wave it about there is extreme distortion of the image around about it. Almost waterfall like.
With Smart smoothing off everything is fine.