So I set it to use the 2080 in Windows' settings, although it was the only option. I then went to the Nvidia control panel and chose the executable. The second setting which says "Select the preferred graphics processor for this program" isn't there. "Specify the settings for the program" is number 2, not number 3 like you have. I believe the 9600k does have an integrated chip, but considering these aren't even options to select it to, I don't think that's the issue.
I then disabled fullscreen optimization, ran the game in windows 7, and ran it as an administrator. None of this solved the issue.
I'm also getting a flickering mouse cursor in the game. I don't know if that's related to it or not.
Thanks for the help. If you have any other ideas, I'll definitely give them a shot. I feel like I've tried pretty much everything. I can record video if necessary.