Weird font issue in Flatpaks

What are these weird little Tofu-like characters in my flatpacks, and how do I fix them?

https://imgur.com/a/B59OY7s

I have CJK fonts installed (most of my fonts are google-noto and adobe)

It renders just fine on web, but not on the official Flatpacks?

I'm on Nobara linux x86.