I am not sure which update caused this to happen but right now the blocks edit for Links are not displaying the cover posts. Here is an example of a blog post:
https://www.drcarney.com/blog/condition-related/smoking-increases-cervical-cancer-risk
The three links just below the blog post are not displaying the cover images for their posts.
https://www.drcarney.com/blog/condition-related/smoking-increases-cervical-cancer-risk
The three links just below the blog post are not displaying the cover images for their posts.