When I deactivate the plugin everything goes back to normal, ie. using local paths.
“Everything”? Meaning what? All your posts go back to the old URLs because that’s not right at all. The plugin doesn’t change your URLs in your images back.
There’s no need to tell the plugin the items are in the buckets because that’s what the search/replace does. Yes, you’ll have the red x for images on the list view of your media library, but that has no relationship with if the image is actually on the server or not. It’s just a way to see if the image was uploaded by the plugin. Nothing more.
the ones uploaded via the plugin are showing even with their permission set to ‘private’.
They should be set to public actually. The plugin sets them to public by default.
Let’s step back a second. Is this what you did?
1) COPY (not move, copy) all the images from your server to DreamObjects
2) Make sure the images are accessible on DreamObjects (just try to view the items in the bucket)
3) Search/Replace the image paths to point to DreamObjects in all your posts