raviS-7

Problem:
The Featured image was missing from the translated posts.

Solution:
It was a compatibility issue between the Default Featured Image plugin and WPML. Either remove the image from Settings >> Media > Default featured image field and press the Save changes button or deactivate that plugin.

Relevant Documentation:
https://wpml.org/forums/topic/featured-image-is-not-showing-for-translations/#post-13754977