LibreOffice running on Linux uses, primarily, “hunspell” for spelling checks.
- You then have to install the language specific “aspell”, “ispell” and, “myspell” dictionaries –
In your case, “aspell-it”, “ispell-italian” and, “myspell-it_IT”.
[HR][/HR]But, there’s also this ongoing openSUSE Forums thread related to LibreOffice not indicating spelling errors – <https://forums.opensuse.org/showthread.php/553684-Libreoffice-spell-check-suggestions-not-visible>.