Hi Marcel,
I don´t have this scenery therefore only a assumption:
Possible, that the designer hadn´t set the “delete runways” flag in his scenery. That´s the only reason what I know at the moment (when the scenery order is correct as you wrote) why you can see double runways …
When my assumption is not correct, the scenery designer can contact us whenever he wants - we try to helping where we can and we have fixed a few such things in cooperation with different scenery designer.
Let me know, when I can do more for you,
Merry Christmas,
Richard