two languages but result is just one pdf for both

Problem/Motivation

Two languages, but only one PDF (for the first language clicked) is being generated.

Steps to reproduce

Whenever generating the invoice. If I have:
- at least 2 languages. English and Chinese Simplified. (zh-hans)
- language for the invoice chosen as site defaulr OR English OR Chinese (doesn't matter).
- doing it as admin, from the configuration page, regardless if the admin is using English or Chinese for interface.
- Generate translations for each of the available languages (on invoice generation) [selected]

Interface shows 2 invoices, as in two translations. But, when I click "download" I only get the download language for the first language I click. If I then click "download" on the other language, it gives me the same pdf.
That is until I delete the invoice, generate it all over again.

So. If I click the "English" [download] button first. Then next time I click Chinese, it gives the same English file.
If I click the "Chinese" [download] button first. Then next time I click English, I get the Chinese file.

NOTE: This does not apply outside of Commerce Invoice. If I use "View PDF" on a node using Entity Print it gives me the correct language PDF for the selected language on that page.