I'ver been through the dance before with this website but the latest update to 1Password seems to have broken it again. 1Password captures the userid on the form (which is encrypted when entered) into the Password field in 1Password and the password on the form into a custom web field. When I try to use the login in Safari (on the Mac) or Chrome (on Windows), the web site UserID field is left blank and the actual userid (captured as the password by 1Password) is put into the website Password field. I end up having to enter the userid manually and copy/paste the actual password from 1Password.
Custom web field with the actual password
1Password Version: 7.6 (70600005)
Extension Version: 7.6
OS Version: macOS 10.14.6
Sync Type: 1Password