As you explain in Kindle EPUB issues - FiveFilters.org Amazon is currently showing titles according to filenames and “For some non-English articles, the title may also appear incorrectly.”
When connecting to Kindle via USB I see such filenames look like
_pastepad.fivefilters.org_[unique-id].azw3 or - if the title contained numbers (like “היום ה-23”)
Is it possible for you to save the files with the original non English titles? It won’t only solve this issue but it’s better in general to be able to browse my files via USB and figure out what they are.
I sent myself a non English file through Amazon’s Send to Kindle by E-mail and the resulting filename was correct:
[non English title]_[unique-id].azw3