I have 2 similar logins set up in 1Password. PayPal - name1 & PayPal - name2. When I set both of them to be transffered to Apple Watch, only the first one alphabetically shows up. If I change the - to a @ for one of them, then they both show up. So it's looking at only a subset of the characters in the login name and not the entire name. If there's a limit on what it wants to use for Apple Watch, there should be a note somewhere.