Mesh (Geometry Split Assimp) pin: UV channel

[CeeYaa]

I have an .obj exportet from Cinema4D - the UV data are saved with in the .obj file as XYZ coordinates Z is always 0 - from the UV channel pin I only get XY would be fine but it takes xy, zx, yz, xy, zx, and so on
did I got something wrong or is there something wrong
I also tried to clean the file but there is always a "0" in the UV channel every third slice and it doesn't parse all "vt .." Textcoordinatepoints in the .obj file
greets CeeYaa