[Risolto] Translating captions

Background of the issue:
I am working on a site under development. I would like to translate the captions to the images set as featured image and embedded into a page/post through the Advanced Translation Editor. I am sure I used to do it this way on other sites.

Symptoms:
The captions don't show in the Advanced Translation Editor, and I have to use the WPML>Media Translations to do this.

Questions:
How can I translate image captions using the Advanced Translation Editor?
Is it necessary to use WPML>Media Translations for translating image captions?