I found that some erroneous logins in Keychain (on the mac) were overriding a login in 1Password4. I got those working by deleting the bad logins in the keychain. I like to use 1Password to login. Should I delete all the logins in Keychain?
You can use iCloud keychain and 1Password at the same time, but it might be best to disable the filling for the keychain if you plan to use 1Password to fill. You don't want things to get confused!