Why Share no longer send from mac to iPhone on Photos ?

OK I had an emergency a few days ago and needed to free up space on my macbook pro as I had messages from Final Cut Pro that my disk was almost full. Before I realized the issue was caused by a very large library in FCP, I moved as much stuff as I could, including Photoslibrary.photoslibraries folder.

Now that I try to bring it back, even by erasing the new one macOS has created, I am being prompted that this operation cannot be completed because there is already such a folder on the mac....

Not sure how related, but now I am trying to share a video from my macbook to that folder (''add to Photos''), I see the usual shaking of the icon on the mac, but the item never appear in Photos on my iPhone.

I tried to disable AirDrop on both devices and relaunched, but to no avail.