Age of empires II definitive edition bugs and problems.

AOE II DE cannot be played in single player campaign mode online, because when you get into the scenarios with a big population the lag times make the game unplayable. Finally figured out that every action was updating online and that caused the lag. Widely
reported on the web, and no solutions that work. So switch to offline mode and it plays fine. But now it seems to write the progress and saved game data to a different place somewhere, so when I log in fresh to go to the next level, after having saved everything
and exited the game, it doesnt know I finished the last level, and can not proceed past the first mission except in a single sitting. Does anybody know where I can find the progress data and place it where the program will find it?

:)