To reproduce, translate Unlikely from Portuguese to English.
Translate the lead paragraph, which includes a footnote number after "4 de agosto de 2017". Publish (to a sandbox).
Observed: The reference doesn't appear at the published page.
The reason is probably that in this paragraph the reference is just <ref name="itunes"/>, and the actual definition of the footnote's content appears in the infobox at the top of the article. If you don't translate it, then CX just doesn't publish the reference.
It's particularly misleading given that the reference number does appear during the translation process.
It would be better if the reference's content would be exported correctly even if the section that includes it is not translated.