Cannot sync CardDAV Contacts in Sierra

I have recently purchased a new computer for my office and it has OS 10.12 Sierra installed; other computers in the office are running 10.11 or earlier. All of these machines are supposed to be set up to share a common Contacts account, hosted on a server (running on 10.8), via CardDAV. As with the other machines, on the new one I have attempted to Add an Account in Contacts' preferences, choosing to "add other account" and typing in the same login credentials that work on other machines. However, I cannot get the Sierra machine to sync.

At first I could not even get the account creation to complete, as it would report "unable to verify account name and password" each time. But finally when I did account creation as advanced and input an initial server path, it at least created the account. However, that account shows no contacts. I have tried numerous permutations of what the server path might be, whether to use SSL or not, different port settings, etc, and never get any cards to show up under that account.

This question posted to Mac OS X Technologies as there does not appear to be an option for a Sierra-specific Community at this time.

EDIT: Re-posted to macOS Sierra Community, finally figured out how to do so.