I noticed a "Game Options" button in the game menu (once loaded into a game) and investigated it.  It's lists all the settings used to generate the world (type of map script, seed, land percentage, etc.), which is cool.  It also lists the "AI Difficulty", and I noticed that it was incorrect.

I had started a game on Empire difficulty, but this screen said "Nation", what?  So I went back to the main menu and loaded again, this time with Civilization difficulty.  Now the screen said "Empire".  Loading again (this time as "nation") I got Civilization.

It appears that the game is using the difficulty setting you picked for the previous game when it generates a new one (and NOT using the currently displayed difficulty).  Loading Nation twice in a row (load, quit to menu, load again) resulted in displaying Nation difficulty.

Note that I do not know if this is a UI error or if it is, in fact, using the wrong difficulty options.

Oh wow thanks so much for that info. I was wondering why everything was so hard on nation and then found out that I was still on Humankind when I looked in game options (probably from my last game of Victor open Dev). You just saved me countless hours of agony :)