I have some parts in an assembly I didn't have a part number to name them when I created them, so I called them something generic, like "silver epoxy". Now that I have the P/Ns I opened each part from the feature manager, and saved the files as the P/N. In the past if I did this from the assembly the part name would update in the feature manager, but for some reason it's not anymore, and I looked everywhere I can think of where to change this so they'll update. I also noticed when I open a part in the tree, it shows mates for the correct part number, which didn't exist when the assembly was first made, so it's picking up on the new file, just not the new name.