Yep. Though I have only just now noticed that your OBS is outdated and Windows DVR Background recording is active. You might want to update your OBS to another build if you weren't already experiencing issues with those.
Does this happen when you record in other resolutions as well? It's an interesting resolution you've got there for sure and being a third of your canvas size and such an unusual frame size... I wonder if the nvidia encoder is having difficulty with it? I'll try that out myself and see if anything happens. Still. I find it hard to understand your original image showing the corruption.
Ok. I tested with your same output settings and found no signs of corruption. Have you tried recording at 840x525 or at 16580x1050? I wonder if perhaps the windows DVR background recording is causing it. It probably is also making use of the GPU's encode capabilities, too.
Have you also tried the x264 cpu encoder to see if the same issue occurs? And did this issue occur in previous versions of OBS?