I recently installed PotPlayer (been using MPC-HC for a while) together with MadVR.
I followed this wiki page, except on Chrome Upscaling in MadVR I choose NGU.
If I choose Standard, very high quality I get around 45-50% in GPU usage, however If I go fullscreen or change the window size a few pixel (increase/decrease by 10) the GPU usage is halved? But on Standard, medium quality it stays around 25% (+- 2%).

Recording: https://streamable.com/ci5t8
Hope it's visible, but the GPU Load goes from about 50% when video is 1920x1080 to about 25% if resize it up/down a few pixels

I'm testing with these video files:

My primary monitor is 1440p (two other 1080p monitors are connected).
CPU and GPU is a Intel i7 6950X and nVidia 1080ti.

I'm not very knowledgeable when it comes to video codec / filters etc. what the do or mean.
Is something wrong, or is it normal for the GPU usage to be halved when the window is no longer the same as the source with NGU?