What I can gather from a quick glance is that all settings except the last 3 are saved in Game User Settings. This is a persistent object (I think saved in UserSettings.ini) and crucially, loaded on game start. The last 3 are saved in a save file which needs to be loaded manually and is pobably loaded manually when the widget opens, hence the described behavior.
If my suspicion is correct you can skip calling OnStartLoadSavedSettings and I bet the sttings saved in Game User Settings will still be applied.
What you should do is take OnStartLoadSavedSettings functionality out of the widget and place it in your GameInstance. (skip loading all the Game user settings too)
For more details you can check this post.