set featured image not working

I have the boxes selected for both:
Set the first [flickr] or [flickrset] image found as the Featured Image. Will not replace the current Featured Image of a post.
and
Set the Featured Image even if one already exists for a post.
but still see the default featured image from my theme, not the posted image.
Am I missing something to change this?

as I’d like to have ‘import images from flicker’ to my media library turned on as a default setting. How can I do this?

thank you

https://www.ads-software.com/plugins/flickr-shortcode-importer/