When I try to use the fill a login feature in the username/password box by clicking on the 1P icon, it only has the option to "Save in 1Password" or "Use suggested password". Given that I have an account with this website stored in my 1Password vault, it does not search and find the account for that site in my vault and show me/let me pick the login info to use when I click in inside of a username/password box by clicking on the icon.
I am logged into 1Password on my Mac, using Chrome 67.0.3396.62 and have only a single Private Vault enabled (the one through my 1Password Families account). This is happening on every site I have tried so far (Google/Gmail, Airbnb, Evernote, LinkedIn).
This is what I can see when I click the icon:
As you can see, I have an account with Evernote and the credentials are store in my vault and am logged into the extension.
1Password Version: 7.0.2
Extension Version: 1.7.3
OS Version: OS X 10.13.4
Sync Type: 1Password Families