In Content translation hovering a sentence in the translation, should highlight the corresponding sentence. Trying recently the Nasothek article form English to Spanish, I noticed the highlight does not happen.
The issue happens for all options of the MT card (Apertium, Google, Yandex, and Copy from source)
In the example below you can see that the highlight for the paragraph is shown when the translation is added but sentences are not highlighted when hovering or clicking them: