Hey @Will, thanks for sharing that thread with me!
I feel conflicted, because I'm on multisite so my *installation* is technically in the root folder, though a site instance is also at /oncecoupled, so it seems as if these problems could be unique.
Was your site also pulling some images, but not others? Since that's the only issue I'm having, it would certainly confirm the same problem is occurring.
This definitely gives me some food for thought. I don't mind waiting on an update if that's the case - I've can stop pulling my hair out in frustration over this!