I suspect you need to edit Chrome settings and tell Chrome where to find some fonts that support Chinese charaters. I'd guess that by default it probably uses a minimal font that only has support for "Western" characters. I'm fairly sure Chrome uses its own fonts not the Kodi fonts (hence the difference).
Chrome and Firefox on x86/amd64 use X window fonts. You could try viewing Demonstration of UNICODE to see results. Sorry for long link. Don't want to put link to own site with same page preserved. If user gets empty boxes instead of Chinese, they only have to install fonts in /storage/.fonts/. If user gets display garbled in some other way, then it is other problem.
Maybe I'll check libreelec on ARM some day to see what you got there. Last time I checked x86 build for Chinese support in browser, it had problem only with missing fonts and extra fonts could be installed in root user's home.