Add value to pot files header "Report-Msgid-Bugs-To"
The pot files on damned lies does not have a value for "Report-Msgid-Bugs-To:" in the header.
https://l10n.gnome.org/POT/gtk.master/gtk.master.pot https://l10n.gnome.org/POT/gtk.master/gtk-properties.master.pot
So i suggest changing:
"Report-Msgid-Bugs-To: \n"
To:
"Report-Msgid-Bugs-To: https://gitlab.gnome.org/GNOME/gtk/-/issues\n"
Or whatever the correct address is.