Hi! I was trying this feature when just by chance found that Spanish (instead of English) is the default language when the Avañe'ẽ (gn) language is set (I'm a Spanish speaker myself; could this be interfering somehow?). You can check this here:
https://commons.wikimedia.org/wiki/Data:I18n/Web2Cit.tab
Switch the interface language to Avañe'ẽ:
- results-header is available both in English and Spanish, but shows in Spanish to me.
- Same thing with fieldname.itemType.
- fieldname.language is available in English and Italian (not in Spanish), and successfully fall backs to English.
- last-check is only available in Italian, and that's what it fall backs to (as expected).