Special characters in file names

Today a user has deleted by mistake 1.5TB of data, I have gone to the trash and there they are, but it is impossible to recover most of them, since special characters (Tildes, Ñ or &) have been added.

My primary storage is S3

Is there something that allows to automatically normalize the file names and remove this type of characters?

Are you saying files that originally had these characters in their names can’t be recovered or that these characters were somehow added to them when they were moved to the trash?

In any case, what makes it impossible? Is there an error message generated?