Materials change resets curtain wall to default

[archbaech]

I am doing a camera view rendering of a curtain wall. I adjusted the material properties using the material editor. All of the curtain wall units in the model reset themselves to the default curtain wall unit. In order to fix this I must now go back and restablish the curtain wall units for every curtain wall. There are hundreds. This is going to take hours. What am I doing wrong and how do I prevent this? Certainly there must be a way to lock the curtain wall units so they don't re-set themselves.