So I have an assembly where I took an existing part from it, saved if off as a new part with a new file name and then replaced the component the new part was copied from with the new copy itself. Without making any changes between the old part, and the new part, I'm having to re-reference every single mate in the assembly that was depending on the previous component. In my experience, when doing this, usually the mates re-associate themselves with the faces, edges, planes, etc. in the new part, given that they are all the same (they are in this case). I feel like I may have accidently turned off some sort of option for mating, but I can't find what it is.