Blogger: Blurry images on related post

I have a problem not typical about blurry images on blogger platform. The blog show blurry images only on related posts section, but these belongs to those images that I have posted on entries/posts together with a YouTube video, for example these post have image-1 image-2 and one video-YT. The other images added to entries "without" a YT video on the same entry/post it does not display blurry images in my related post.

Here is an example of an image from my blog. As you can see, the template is resizing to s72-c.

The template designer don't reply with a solution, after 15 days waiting for it. Please I need a help for this, I google this case but I don't find how to solve it. thanks in advance

</div></b:includable><b:includable id='snippetedPostThumbnail'><div class='item-thumbnail'><a expr:href='data:post.url'><b:include data='{                         image: data:post.featuredImage,                         imageSizes: [72, 144],                         imageRatio: &quot;1:1&quot;,                         sourceSizes: &quot;72px&quot;                        }' name='responsiveImage'/></a></div>