Can't Edit Text in Photos Application

I'm trying to edit the my photo titles, description or keywords in the Photos OS X application. I have the photos in a shared album.

I'm following instructions here http://www.imore.com/how-add-and-edit-title-description-and-keywords-photos-os-x, which all seem to work to a point.

I open the photo properties with Command-I, the edit cursor appears as I hover over any of the text fields, but the text is not editable. Typing doesn't create any text.

So, I then select the Option-Click menu and select "View in Library". Here I can use the same Command-I option for each photo and the edit cursor appears and works.

However, the new titles etc that I write for the photos are not replicated back to my shared album.

Any ideas on how I can edit photo text in the Album, and if not, how I force the edited version from the Library to sync to the Shared Album?