First - please note that I never said you were using two monitors. Somebody else assumed that.
Now, did the change (above) affect the banding?
Otherwise, I still think you should check with nVidia support. The folks here are good, but we aren't nVidia. So, talking here about problems that are (fairly certainly) nVidia's, doesn't help fix them.
[If the code is (arguably) "standard", and many video cards/drivers/monitors display it OK, and some don't - perhaps.................]
Bottom line: I believe that an appropriate question for this forum to ask is: "What did the vendor say?"
Dale I appreciate your help in trying to get this figured out. I will try to be detailed with my answers so hopefully I won't miss anything.
1. please note that I never said you were using two monitors. Somebody else assumed that.
Yes I understand, I was quoting Edgar's response.
2. did the change (above) affect the banding?
Increasing anisotropic filtering and antialiasing? No change.
I'm not the "expert" but I really don't think it's the monitor. I would have noticed abnormalities long ago, plus my laptop has the same effect.