bug with .dds pictures

[Scotvince]

I don't know why converting an image into .dds with xn convert doesn't work. The final image is completely hatched as you can see on the screenshot.

https://imgur.com/g26P2ez

To precise the problem, the littles black&white hatched pictures you see in the center of the screenshot are in .dds into the game files. I convert pictures from png to .dds and I integrate them in the game. All online converters create correct photos, but not xn converter (which I need to use because of the multiple conversions possibility). Using xn converter from .png to .dds creates hatched photos.