Flatpak CJK Font Issue

Telegram and Bitwarden (Flatpak) showing missing/broken Chinese characters, while VS Code and Brave display them fine.

Problem: Flatpak apps use bad default CJK fonts and can’t access system fonts.

Fix:

Wait for Flatpak to support global font overrides, or manually set font conf for each app.

for each app

Use flatpak list | grep -E "(telegram|bitwarden)" to know the name of the Flatpak app.

As an example , create ~/.var/app/org.telegram.desktop/config/fontconfig/fonts.conf with the following content:


<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
  <match target="pattern">
    <test qual="any" name="family">
      <string>serif</string>
    </test>
    <edit name="family" mode="prepend" binding="strong">
      <string>Heisei Mincho Std</string>
      <string>Noto Serif CJK JP</string>
      <string>Noto Serif CJK SC</string>
    </edit>
  </match>
  <match target="pattern">
    <test qual="any" name="family">
      <string>sans-serif</string>
    </test>
    <edit name="family" mode="prepend" binding="strong">
      <string>Noto Sans CJK JP</string>
      <string>Noto Sans CJK SC</string>
    </edit>
  </match>
  <match target="pattern">
    <test qual="any" name="family">
      <string>monospace</string>
    </test>
    <edit name="family" mode="prepend" binding="strong">
      <string>Noto Sans Mono CJK JP</string>
      <string>Noto Sans Mono CJK SC</string>
    </edit>
  </match>
</fontconfig>

also do it for com.bitwarden.desktop