Boxes as text for other languages

I have been looking for this plugin, only to come to a dead end again.

The plugin works fine, but it fails to display text in other languages like Traditional & Simplified Chinese. Refer to the site I am currently working on: chateaumaryfrancewine.com, go to Catalogue and select a product. You won’t see it now as the site is live and I removed it, but you’d get boxes as text. Literally “????”. If I copy and paste the boxes in anything else (i.e fields etc), it appears in Mandarin characters. It looks a little better as a Word document, and is perfect if I click on Print icon.

Maybe there is something you can do to fix this?

https://www.ads-software.com/plugins/woocommerce-pdf-print/