The filename you talked about above (username, author, filename) is basically a label, not the actual filename that opens when you click the label/link.
So just to check. When you have a submission in the submission stage, you have a filename like this:
username, author, filename
When you then click on "Send to review" and move to the review stage, the filename you see in the review files panel is still the same?
If so, that should not happen.