I see the images in your feed, but perhaps they don’t like the responsive images code added by WordPress, seen in the srcset below:
<img width="300" height="161" src="https://neavision.it/wp-content/uploads/2019/07/webmagazine-min-300x161.jpg" class="attachment-medium size-medium wp-post-image" alt="webmagazine" style="margin-bottom: 15px;" srcset="https://neavision.it/wp-content/uploads/2019/07/webmagazine-min-300x161.jpg 300w, https://neavision.it/wp-content/uploads/2019/07/webmagazine-min-768x413.jpg 768w, https://neavision.it/wp-content/uploads/2019/07/webmagazine-min.jpg 1024w" sizes="(max-width: 300px) 100vw, 300px" />
Feedly may require larger images of a certain size:
“If the first img in the story has a height and width greater than 450 pixels, that first image will be selected as the featured image. If not, Feedly will try to pick the largest image in the story.”
https://blog.feedly.com/10-ways-to-optimize-your-feed-for-feedly/
Our premium version does offer a Disable Responsive Images option, with a free 14 day trial if you’d like to see if it works for you.