The username is not filled at login.salesforce.com.
I have tried the manually saving the username and password. When I click the url, only the password field is filled.
The input textbox for the username is type=email and there is no "email" type in the field list.
1Password Version: 126.96.36.1996 (24)
Extension Version: 188.8.131.52
OS Version: 6.2.9200
Sync Type: Not Provided