[Smush Pro] Some Images & Icons Not Displaying

Hi, I got Smush Pro about a month ago. Ever since I activated it, I've noticed that certain images and icons are not displaying correctly.

Firstly, icons like the social media links in the upper right corner of my site and the home page button on the left side of my main menu show up as boxes, at least on Chrome and Firefox; on Safari those still seem to display correctly. I'm not sure how to fix it so that those icons display correctly, across web browsers.

Another big issue on all three web browsers is that several images don't display correctly. Many of my featured images on news posts (and those featured images pulled for the home page) don't show up, instead showing a default icon and the title of the missing image. However, this only happens for some images. Many of my posts' featured images do display correctly.

I've tried changing several settings but nothing has resolved the issue. How can I make it so the icons and images always display correctly?

Thank you!