OK speaking with upstream we think this is likely a xdg-desktop-portal-kde bug, so I am marking this as affect that project and marking as invalid for flatpak.
I'm also trying to work out how to report a bug against https://phabricator.kde.org/source/xdg-desktop-portal-kde/ if I can figure it out I'll link it back here :-)
OK speaking with upstream we think this is likely a xdg-desktop- portal- kde bug, so I am marking this as affect that project and marking as invalid for flatpak.
I'm also trying to work out how to report a bug against https:/ /phabricator. kde.org/ source/ xdg-desktop- portal- kde/ if I can figure it out I'll link it back here :-)