Question: In ChessBase 17 there is a new function. When you open a new board window, it automatically opens the last game notation you used. I must then start a new board window each time via Menu New -> Board Window, so that I can continue working and enter a new game.
Answer: You can disable this feature permanently. This can be done via menu File - Options - Save in the category "Save".
On the right side under the entry Save -> "For 'New game open last game". Deactivate the entry and confirm the default with "OK". With this the program ignores the last lot loaded in the last session.