Downloaded PDFs being renamed

This issue has been kicking around for a while but has anyone found a workaround for this yet? Where a PDF file is made available for a user to download but it gets renamed to some ridiculously long alpha-numeric name?
I’ve seen a few workarounds involving coding and linking to external servers etc, but those aren’t ideal solutions if the client needs to manage the items in the CMS.

Wix Studio.

Thanks Chris. Can i just confirm a couple of things?
With the CMS, I’m just using the built in Wix Studio CMS, regarding ‘CMS settings’ where might I find such settings? None that I have looked at mention filenames.
Also by ‘Rename Files Before Download’, is there some criteria as to how they should be named? I did experiment with renaming them but it didn’t seem to make any difference.