Why does Mac iCloud Keychain create so many entries for a web site?

Looking through Keychain on my mac, I see multiple entries for the same web site, though with different dates. I kind of expect it to save the latest only.

Above is the list without my email address (left hand side of page). Below is the right side of the page. The same email address is used in each. I have not checked to see if the passwords are the same in each case.

Is there a setting I'm missing, or is it working correctly? I've been confuzzled for a while.