Have you tried the key combination option-command-S instead?
As a bow drawn at venture I'd try to delete the cached preferences files for the Photos.app and then restart the Mac. This file can influence the graphical user interface.
I'd delete the complete folder ~/Library/Containers/com.apple.Photos/ and restart the Mac, then try again.
Your user library may still be hidden.To reveal the hidden User Library:
- Bring the Finder forward by clicking on the Desktop or the Finder icon in the Dock.
- Select your user/home folder (with the house icon in the Finder sidebar)
- With that Finder window as the front window, press the key combination ⌘J to bring up the View options.
- In the View options panel enable ’Show Library Folder’. That will make your user library folder visible in your Home folder.
- Open your Home folder, then the Library folder, then Containers.
- Move the complete folder ~/Library/Containers/com.apple.Photos to your desktop. Move the entire folder, not just the contents.
Now restart the Mac and try again. If all is well, delete the folder from the Desktop.