How to get the URL for a public album in Photos that has been marked as public website

I am running Photos 4.0 on macOS 10.14.6

I have enabled shared albums (System Preferences -> iCloud -> Photos options -> Shared Albums)

I have created a public album and added photos to it

I have clicked the checkbox to make it public website

How do I found out what the URL is for the public website? I think Photos is supposed to change the text "allow anyone to view this shared album on iCloud.com" to "anyone can view this album at ...some-url...". That does not happen for me.

Also, when I invite people to the album, they do NOT get an invitiation email (yes, I checked the junk folder). Instead, a question mark appears next to the e-mail address in the "invite people..." list in Photos.

Also, anything related to shared albums is extremely slow; for example adding just 3 normal size photos to a shared album is stuck forever (I waited hours):

After about 48 hours of waiting (connected to the Internet), the URL suddenly appeared: