This has to do with how Proe finds parts in an assy that you open. When you open an assembly, Proe will look for the parts it contains in the following order:
- In session.
- In the folder the assembly came from, regardless of if this is your working directory or not.
- Your working directory.
- Your search paths, if defined.
There are also Windchill paths in the mix somewhere, but I'm not sure where they fit.
So, if you want your modified parts to be inserted in that assy, you need to open them first.
This has been the order Proe uses for some time, going back I believe to WF1. Before that I think items #2 & #3 were reversed and I seem to recall there being a config option to restore the old order. I searched for it, but couldn't find it (It's not file_open_default_folder, that only sets the default folder displayed when selecting file > open. It has nothing to do with the order parts are retrieved.)
Is it possible that option was set in your install of Proe? You didn't say what versions of Proe & Creo you're testing.