What is Mac Photos doing after I turned iCloud off then back on?
I recently imported 66 photos onto my MacBook Pro (2021) Photos app from a camera, but it was taking a while to sync (i.e. after several hours, it still said "uploading 66 items"). On my old MacBook this sort of thing happened often, and the forums are full of questions about iCloud photos sync getting "stuck".
Usually (with the new MacBook Pro) it all works fine and my Photos library (over 50k photos) is synced across my MacBook, iPhone and iPad. I have "Download originals to this Mac" enabled.
After some time, I decided to follow some (possibly bad?) advice and turn off iCloud photos on the MacBook, then turn it back on. Now it says "uploading 53,816 items".
What is Photos doing? Is it re-uploading my entire library to iCloud? If so, will I have duplicates of every single photo? And if so, how can I stop it from doing this? I would obviously like Photos to intelligently realise that almost all of these are already on iCloud, and only upload the 66 outstanding photos.
Thanks x