Hi, need help regarding make independent solidworks assembly

hi, I had made an assembly that uses three instances of an assembly, these assemblies were inserted individually and not through the component pattern. now after inserting these assemblies I have made individual and specific changes to the th parts in them, with the intention that I will later propagate the changes to part level after I had made those parts separately independent. However, whenever I try to make a certain part independent it not only replaces that part in it's assembly but also the ones in the other two assemblies. No am I using the make independent wrong or is it a bug. please advice. It's the wheel assemblies in the picture.

SolidworksAssemblies