I have a dragon model from Sintel. And I redid the texture map, combining all the individual 4k x 4k body parts maps into one large 8k x 8k texture png map.
When the mesh is in object mode then the texture appears correctly. However when the object is in render mode, the texture map is all misaligned.
Seems like all the rendering is only using the upper right corner of the 8k texture.
searching for the fix.
I unpacked and deleted the old textures. And re packed the new 8k map. I cleaned out all the old materials as well. So there is only one material map left - the 8k texture map.
Here is the dragon in object mode –
Here is the dragon in working window render –
And here is the 8k texture map