How to save and load material object?

Hi everyone,I’m try to save the object material and load material I just saved.But I had trouble in blueprint script.
just like the picture 1&2 (save and load function), I just use base_Furniture actor bp to store my object to change its material and mesh. But I found it wrong when I use save & load . I just want it save material as variables and store it in the array and load by it’s material I just saved one by one. But I can’t!!
the two are the same bp(base_Furniture) but one can load the right material and another can’t .
Am I wrong with bp logic. I want to save all the bp(base_Furniture) object’s material in array one by one and load it. Thank you for your help and sorry my English not good at all.

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