[NSFW] Featured image does not display in translated version

I use Lingotec to create a clone of that page. Only difference should be the title to which I appended the text ” – ES”.
https://vc-alternative.com/es/vc-a-newsletters-espagnol/vc-a-winter-2021-newsletter-es/

In the Spanish version (same as in the French one), the featured image, which should be https://vc-alternative.com/wp-content/uploads/2020/12/2021-scaled.jpg does not show up. It is replaced by the image https://vc-alternative.com/wp-content/uploads/2020/11/slider-vca-1.jpg which is used in other pages of the website, but not this one.

If I change the “featured” image in the Spanish or French version, nothing happens. If I delete it, then, the other image disappears as well.

The page I need help with: [log in to see the link]