Hello.
In the case of an object with multiple mesh inside it, and each mesh using different texture, you had to texture each mesh manually to its texture.
It's discussed in this thread:
https://forum.thegamecreators.com/thread/216386
The commands looks something like this:
LoadObjectWithChildren( 1, "shu/shu.x" )
LoadImage(1,"shu/eyer.png")
LoadImage(2,"shu/eyel.png")
LoadImage(3,"shu/face.png")
LoadImage(4,"shu/shirt.png")
LoadImage(5,"shu/hair.png")
SetImageWrapU(1,1) : SetImageWrapV(1,1)
SetImageWrapU(2,1) : SetImageWrapV(2,1)
SetImageWrapU(3,1) : SetImageWrapV(3,1)
SetImageWrapU(4,1) : SetImageWrapV(4,1)
SetImageWrapU(5,1) : SetImageWrapV(5,1)
SetObjectMeshImage( 1,1,1,0 )
SetObjectMeshImage( 1,2,2,0 )
SetObjectMeshImage( 1,3,3,0 )
SetObjectMeshImage( 1,4,4,0 )
SetObjectMeshImage( 1,5,5,0 )