Hi again, @dmoyes
I was looking at this issue with @Jussi_Aaltonen when we realized that there is a way to work around the maps changing while a fix is being worked on.
If you don’t have any of the displacement features in use (displacement, shutlining, edge softening) disable the displacement plug-in (load-protect) and restart Rhino. Now uv-mapped textures on sub-objects should work.
Remember to turn the Displacement plug-in back on if and when you need the functionality it provides.