I am new into the inkscape community and I am very glad to have discovered a free tool like this!
I am trying to create my own graphics for my 2D game and I am stuck when I apply a stroke on a 3D Cube :

As you can see, the stroke of the two rectangles juste overlap ... I tried to merge the nodes but it does not work, actually, it did nothing...
Thank you for your reading and I apologize for any english mistakes