GNOME Mahjongg license shown as Proprietary (due to CC-BY-SA-3.0)

I just noticed the GNOME Mahjongg application shows its license as proprietary in Fedora Rawhide, which uses 40.0 Software and appstream 0.14.3. The issue might be lower in the stack though, not in Software. The license in appdata is: <project_license>GPL-2.0+ and CC-BY-SA-3.0</project_license> and Software 3.36.1 with libappstream-glib-0.7.17-1.fc32 shows it as such (both licenses).