LibreOffice Japanese Language

I have LibreOffice 7.4 installed but when switching the interface to Japanese language the actual Japanese characters are not shown. Just the hex codes of the characters.
I tried to download the Japanese language pack from LibreOffice webpage, but Endless do not allow the installation.
The OS interface and all other applications display Japanese characters properly.
The problem is only in LibreOffice.
Could somebody suggest a solution?
Thanks!