MEDIA LIBRARY NOT SHOWING THUMBNAILS with WP SMUSH PRO

Suddenly my media folder stopped showing thumbnails for newly uploaded images. (see screenshot below) The problem also happens when I insert new images into content. Shows in the code and on live pages, but not in the preview.

I deactivated all the plugins and activated them one by one, testing the image uploads. So I isolated it to the WP Smush PRO. When active this problem exists. When deactivated, the problem disappears. Any thoughts?