WP Smush Pro Plugin Freezing while attempting to smush in bulk!

I am having trouble with the WP Smush Pro plugin. Each time I try to bulk smush a lot of images, I get a little over 5,500 images and then it just freezes and the loading dots starts spinning with "Smushing in Progress". I have kept the tab open for 6+ hours and if I do close it when I go back to it, it still keeps spinning. Not sure what is making it freeze after 5638 of 7020 total attachments have been smushed.