Japanese texts in Gtk.HeaderBar of Flatpak apps are shown in serif font instead of sans-serif, as you can see the word "ドキュメントビューアー" (means "Document Viewer" in Japanese) in the following screenshot:
FYI if you select Adwaita instead of elementary stylesheet it shows in sans-serif as expected, so I assumed this is a stylesheet issue:
Steps to Reproduce
Open some Flatpak app with Gtk.HeaderBar in Japanese in the following steps:
Open Terminal
Run flatpak run --command=sh org.gnome.Evince
Run LANGUAGE=ja evince in the sandboxed terminal
See the headerbar: the Japanese text "ドキュメントビューアー" is shown in the serif font instead of a sans-serif font, as per the following screenshot:
Expected Behavior
Japanese texts in the headerbar of Flatpak apps should also use sans-serif same as other widgets, like this:
What Happened?
Japanese texts in Gtk.HeaderBar of Flatpak apps are shown in serif font instead of sans-serif, as you can see the word "ドキュメントビューアー" (means "Document Viewer" in Japanese) in the following screenshot:
FYI if you select Adwaita instead of elementary stylesheet it shows in sans-serif as expected, so I assumed this is a stylesheet issue:
Steps to Reproduce
flatpak run --command=sh org.gnome.EvinceLANGUAGE=ja evincein the sandboxed terminalExpected Behavior
Japanese texts in the headerbar of Flatpak apps should also use sans-serif same as other widgets, like this:
OS Version
6.x (Odin)
Software Version
Latest release (I have run all updates)
Log Output
Hardware Info