I use `set-fontset-font` to set the fonts for my language, and I noticed that only latin fonts will be affected by `text-scale-adjust` while the asian fonts remain the same size.
But the scaling does work when using emacs without a config file (`emacs -Q`) or when I didn't specify the fonts via `set-fontset-font`.
[My emacs config file can be found here.](https://github.com/funk443/dotfiles/blob/master/.emacs.d/config.org)
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[Check this site for solution.](http://baohaojun.github.io/perfect-emacs-chinese-font.html)
[With my config.](https://preview.redd.it/7m7oaxutlkc91.png?width=272&format=png&auto=webp&s=29a50432b68971ad0fd2a581659b5ef5410e3509)
[Without a config file.](https://preview.redd.it/bmlwh1llmkc91.png?width=413&format=png&auto=webp&s=e8fb24d4fecdde493b3e80185465d4d2e0e918b6)