I turned on some of the WP Smush settings and it screwed up a lot of my media files and caused;
1. Some images to not show up on some posts/pages as featured image.
2. Some images not to show up within the post
2. Some images to not show up in the media library (even though the thumbnail in the library shows & the hard files are accessible on the server via direct link)
3. Some thumbnails not show up in the media library (even though the hard files are accessible on the server via direct link).
4. Some images to say they are attached to posts that they are not.
5. All of the above. Yet, the hard files are all still there on my server in the uploads folder).
6. some image galleries within posts not to show.
Some it didn't effect at all.
Basically, it made a mess of my media library and some images (and their attached posts).
How do I resolve this. Re-uploading them all is not an option as I have too many posts.