Hi,
You provided me ftp login and it is all good. But you forgot to provide me username for admin panel. You just provided password. Could you please share the username as well?
Before you provide me the information, please run the regenerate thumbnail plugin once.
https://wordpress.org/plugins/regenerate-thumbnails/

Hi,
Your circle featured images looks okay on the right sidebar.
You can go to dashboard > appearance > widgets > blog sidebar > you can add or remove them.
If you want to change the style, you can use this custom css code;

.widget_recent_comments ul li a:not(.url) { text-transform: none;  text-decoration: none; }