Hey, this has worked before and I have the setting checked under browser settings. I would like it to work so that sub.example.com also prefills with the credentials stored in 1Password as example.com. I am using the browser-extension for Safari 10.0.1.
1Password Version: 6.3.5 (635001)
Extension Version: 4.6.1
OS Version: MacOS 10.12.1 (16B2555)
Sync Type: iCloud