Paolo- Thanks for posting this. I am curious to learn what is causing it.
I have also had an experience similar to this. Are you using Nanosound CD to extract cd’s?
My SSD drive had a directory called VolumioLib where my music library was stored.
Recently I discovered that there was a new directory called VolumioLib_ which contains the music library and the original VolumioLib (no underscore) is still there but empty.
I’m able to specify VolumioLib_ (with underscore) in the extraction path and Nanosound CD will extract to it.
I’m curious how this was created. I haven’t done anything intentional with the structure of that drive.
Side Note: there is also an EFI directory that was created when I initially formatted the drive. It was magically cloned as EFI_ as well.