[2021] mouse cursor slowly dies when I start Anno 1800

Hello, please help!
Anno 1800 run well on my system until last update (a bit over a week ago?). But since every time that I start the game my mouse cursor slowly becomes less responsive. The hand movement translates to less and less cursor movement and some clicks just don't do anything. After a few minutes, sometimes after half an hour, its absolutly unplayable. This effect is also there when I minimize the game. The second I close the game, the cursor works fine.

Thank you for fixing that! I love the game and would like to play again!
Best regards