[BetterRed]

What is the context of those screenshots - file manager, spreadsheet, calibre book list ?

I'm guessing the underscore ( _ ) after the Volume number was a colon ( : ). Some OS/FS combos do not allow colons in folder and file names, others only allow Latin chars (i.e. no cyrrillic, katagana etc) - calibre caters for all the variants via normalising algorithms.

As stumped has posted you will find the true values in the database which is what you should see in the book list, you can use those values in Save to Disk and Send to Device Templates.

If you obtained those books directly from another calibre library then depending on your Add Books settings you may have used the ascii-ized, sanitized, latinized, truncated names that calibre wrote in the other library as the 'true' values in your library.

BR