Jan, without your .ad4 file to see exactly how you applied that texture, I can only guess.
It appears you have repositioned the vertices from their initial position as placed by ADE-GP so as to align the crosshatch with the real world. In doing so, you have ended-up with a different scale in each poly. The solution is to enlarge or reduce (on the ADE-GP Editor) one poly or the other relative to the texture size until the two match. Use the ADE_GP Editor Resize feature
Unfortunately, once you move the vertices and/or change the scale, ADE-GP "forgets" the original positions/scaling and the rest is up to you. With scale-sensitive textures such as cross-hatch, that's a pain, but polys of different sizes require different scales to maintain uniform line-spacing/width.