Keyboard layout switch not working for many applications

I've configured Gnome such that keyboard layout is switched from US to German while AltGr is being pressed. Under X11, this works for all applications but under Wayland it works for some but not others.

Here are some applications I tried on Debian where keyboard layout switching works (✓) and where it doesn't work (✕). Maybe someone can see a system in this list.

• Blender ✕
• Emacs-gtk ✕
• Firefox ✕
• Gimp ✓
• Gnome-terminal ✓
• Google-Chrome ✕
• Google-Earth ✕
• Inkscape ✕
• LaTeXila ✓
• LibreOffice ✓
• Mathematica ✕
• Nautilus ✓
• Minecraft ✕
• Opera ✕
• Rhythmbox ✓
• Shotwell ✓
• Skype ✕
• Telegram ✕
• Thunderbird ✕
• Vivaldi ✕
• XTerm ✕

This is a common problem seen on many distros and reported before [e.g. Ubuntu, Fedora]. I reported this as issue #147 on Freedesktop.org and they sent me here.