Our 2nd Tier Support checked and we're able to fix the Chinese Language page here hidden link by removing this file "plf-filter.php" in the mu-plugins folder.
As your 2nd tier support rightly claimed, removing the plf-filter.php file resolves the issue.
This file is part of the plugin called "Plugin Load Filter". hidden link. The purpose is to reduce the plugins loaded on specific pages, selectively. For instance, it can stop the CF7 form from loading when it is not used on the homepage. In this way, it makes the pages load faster.
I have other websites that also use this plugin without issues. But because it conflicts with WPML, I will stop using it henceforth.
Please thank the 2nd tier support on my behalf. Also, thank YOU for being patient.
