Thank you for your reply! Now I know what’s causing the problem.
I have freshly installed ubuntu 22.04 and Onlyoffice, everything test ok, characters in various languages are displayed normally.
After switched ONLYOFFICE Docs to HTTPS protocol, the display issue comes up.
My swith steps:
cp -f /etc/onlyoffice/documentserver/nginx/ds-ssl.conf.tmpl /etc/onlyoffice/documentserver/nginx/ds.conf
Edit /etc/onlyoffice/documentserver/nginx/ds.conf add my domain cert pem/key files
bash /usr/bin/documentserver-update-securelink.sh
restart onlyoffice
I cannot provide the original file, my test step is just open the: https://onlyoffice.mydomain.com/example/, and create a new.docx or new.xlsx, then input some chinese or japanese words.