IF I use the PIKTURES app to move the photo, then it works seamlessly.
If I restart, I believe the Apps and Image viewers re-index or whatever, and now all 3 photos show. Same thing in the Gallery app (the other 2 continue to show. BUT it doesn't show in the image browser (the other 2 continue to show, the moved one is not recognised as a photo). Now, if I take a pic from internal storage and move it to the SD Card (in the same location as the previous 2 photos), the File Manager moves it. These are showing fine in the Gallery app (irrespective of which one I use) and showing fine in File Manager (image browser AND the actual folder).
Going to the folder itself in ES explorer shows the file, but in the Gallery view (of the app or ES explorer) the picture doesn't show unless I restart the device (or perhaps clear cache or whatever). It simply doesn't SHOW in the Piktures App (or Google Photos) after I have moved the file to SD Card. ES explorer DOES have permission to access SD Card.