Previous QtLinguist (Version 5.5.0) showed translations into other languages like this:

Showing each language with it's name in English.

However, the newer QtLinguist (Version 5.12.8) shows it like this, with the language names in the native tongue:

I'm not sure if this change was intentional (I can see some cases where it might be desirable) but it is not helpful, since when trying to manually do the translations the developer cannot recognise which language they are trying to get the translation for.

Could this at least be something that could be set in a preferences menu? (or have I missed an option somewhere that already allows for this?)