I have automatically sign in after filling usernames and passwords ticked. Some sites this works as advertised. Many open the website and I see the data filled... then instead of being logged in I'm again shown the login screen without any credentials filled in. My workaround is to use the Command-\ shortcut. This works on most sites.
The one site Command-\ shortcut doesn't work is gmail logins. It worked in 1PW6 and the original 1PW7, not sure if google changed something or 1PW7beta is at fault. I have multiple gmail accounts I use daily.
Another thing and perhaps a separate issue is the "automatically sign in after filling usernames and passwords" when I first ticked it had a tick or check mark as expected. I then switch to Safari and use the 1PW mini, I expect the data to be filled automagically. Doesn't work. Switch back the 1PW app and the preference is unchecked. I did this 3, perhaps 4 times before I was present with the instructions to enable the needed script to be installed in the Library. Since I was on a new, for me Mac, the Library was hidden. It had been years since I enabled that on another Mac, so I had to figure that out, perhaps that info can be included to make it easier for others.
1Password Version: 1Password 7 Version 7.1.BETA-0 (70100000) AgileBit
Extension Version: 4.7.2
OS Version: 10.13.5 (17F77)
Sync Type: Dropbox