You are right, it does not make sense. Checked you NVidia control panel (reset to default?)? Something is off at 28.8% GPU.
What I do for graphic options, I fly, go external, have a good background with trees, rivers and buildings, hit escape and go to options and I can see some landscape, have all graphics on LOW or OFF, but TEXTURE QUALITY on ULTRA, and then manipulate parameters one-by-one, have
on standby, and every time you hit "F11 Apply … " you can see live results, Resume, wave you head around and check for lags, I get 29-35 on a miserable 8600K/1080 machine.