Well, I found the culprit.
It seems to be an issue with the option “Hide cropped images from media dialog” under Settings -> Media -> ACF Image Crop Settings. If it’s enabled, then the admin won’t see the cropped versions in the media dialog, however when this option is enabled, the user is not able to edit the cropped images from the post edit page.
Once I unchecked this option, the edit works fine. The only drawback is that the admin will see all the images in the media dialog, including the cropped versions.