replacing picture naming issue

I've been having this issue as well. I noticed that some of the image filenames in one project had some special characters in them, I didn't want that to be an issue "down the line", so I renamed the original files. But no matter how I tried (import, drag/drop, replace picture), the new image would arrive with the old filename. Very frustrating. I also tried deleting the temp files, and saving the file again from an editor (Snagit Editor) but that didn't seem to work either. The image would always import with the wrong filename.

I then started a new project and imported the renamed image. Success! But when I tried to import the new slide from the new project into the old one, the image would arrive with the old filename! Argghh.

So, I went back to the new project and since the Media Library has an export feature, I thought I'd try to export the image with (another) new filename from there. When I imported that file into the new project, it worked. SUCCESS! The filename did not revert to the bad one. 

Maybe this was a one-off solution (I was trying a bunch of different things before I found this thread), so YMMV.