Featured image caption

@alberto Bonis,

try directly under Media – Library (List mode) with the language switch buttons.

Just tried, under the image appear

[:it]Raffaele Mancini, chef e docente ICIF[:en]Giancarlo Lercara. AIS Somellier and ICIF teacher[:]

Then this will be also – Desirable Unimplemented Features: Read
Media Library: more fields to be translated
Sorry for now.

@alberto Bonis,

I did a little test, but here it works. (?)

Try a default WP theme and see if that makes a difference.