Image editing flakiness

I’ve edited the original image in the post editor. Which I save, applying changes to all image sizes. Fine, I then go back to my post and the cropped image appears. When I click on the image it takes me to the original uncropped image!! WTF

Hang on a second I edited the original and saved it!! Surely if you edit an original you overwrite the old image, you lose it, no ifs no buts! Not only that but if I go into the media library there is no sign of the original anyway. Where’s it coming from?

20 mins later I tried the above and there was no sign of the original. Can anyone explain this or is this just the flaky side of WP? Confused!!