@pizzaro
When installing GP3 you are converting the original image to an GP3 image. It even has it's own feeds. This is no longer an original image. It's doing deep modifications to the whole system. So nobody here can help or support you with your problem, as this problem is NOT related to the original image from DP anymore.
As said before go to https://www.i-have-a-dreambox.com/wbb2/ if you need support.