Different number of rows between PowerQuery Editor and Data view

Hi all,

i'm certainly have an issue in PowerBI. In the query editor i have an Table with 450 rows. When i click "save and apply" and load the data, the data perfectly loads with no error message or something. But: the same table comes out with only 200 rows. There is no filter or anything. Can someone explain this?

Now it's getting interesting: I added a new step in the query editor and then reload the data. The result was that i got all 450 rows. So i updated the data modell in powerBI online and activated the automatic refresh. After the next refresh the table again only have 200 rows. I have no clue..

Thank you for any idea!