"Not processed" in Preview window

I’m using version 4.00 for the first time, lots more settings than the older version. I’m 10 hours into upscaling a video using Proteus. In the 2nd preview window it says says “Not Processed”. What does this specifically mean?


We’ve updated the messaging for preview status in version 4.0.1:

This will make it clearer when a preview section is unprocessed, in-progress, or complete.

I do not understand how the in-progress preview works. The dimmed window looks exactly the same as the original window. The fact that it is dimmed has taken all resolution out of the video so it looks exactly like the original. How to I do either the split window to see actual improvements or dual windows with improved video while it is porocessing?