I'm experiencing a couple of problems editing 3D video using the latest versions of V19 and V20. Specifically, when I set the project to 3D the width gets reduced to 8 pixels, and I cannot change the 3D preview setting.
I am using a new laptop, with details in my signature, but I saw the 8 pixel quirk on my older HP laptop too.
Here's an example, step by step:
I loaded a couple of 3D images to a 1080p project:
Set the project to SBS full and the width is changed to 8 pixels which I correct by resetting the width:
Next I set the media properties to sbs full:
Finally I try to change the display mode to anaglyph, but nothing changes: