Setting save if you set them in screen b4, Not in actual screen when you already set up players

I've followed the same steps again with Process Monitor open this time, and I  found that it succesfully reads from

C:\Users\[user]\AppData\Local\Ironclad Games\Sins of a Solar Empire\Setting\diplomacy.user.setting

at startup, it also writes the changes successfully.

It just doesn't use what it finds for some reason.

Ok you have two screens with game options button.

First is one where you can choose maps as well. If you change settings on this one game should remember for next time..... as long as you finish the game and it does not end up as crashed game.

Second is one that shows after you press host new game button and it gives you screen with players that joined and option to chat it. Game wont remember settings you choose from here. Also If you change settings and do not play accept before someone else joins the game settings will reset so you will have to change again

The reason for this is to get rid of differences between options  what shows on game description screen and when you actually join the game.....

Hope that helps