Hi @AEssop ...
Have you tried clicking on the first file that you want to unpublish, then holding down your Shift key on your keyboard, and then selecting the last file that you want to unpublish? This will select a range of files (similar to that of selecting a range of files in your Windows or Mac file explorer windows). Then, there is an icon at the top of the "Files" screen that looks like a cloud with a padlock on it. This is the "Manage Access" button. Click on that, and you'll be able to select whether or not those selected files are published nor not...along with a couple other options.
Hope this helps!
