OBJ transform - lost texture map image on export?

I’m new to texture maps so I’m sure this is achingly simple but having not found an answer yet online I’m looking for a helping hand out of the deep quagmire of texture maps!

I’m importing an OBJ with a texture map and doing a simple transformation back to the world origin to export out again. But in doing so I lose the .png picture file on exporting (.mtl is still there). Bake doesn’t seem to be the answer. What obvious thing am I missing?

Thanks!

make sure the object has a material and make sire you use the save textures option when exporting-