Contact Matching Rule fails to catch duplicates in Lightning Experience

This problem stems from a gap in Lightning Experience surrounding Contact creation, which is exposed through the use of Duplicate Management. Standard Contact Matching Rule evaluates the 'Mailing Address' field whenever the lookup to Accounts is populated. The system uses this information to warn users of potential duplicates prior to Saving the record. This works without issue in Aloha (Classic). When a user populates the Account lookup in Lightning (on new Contact creation), the 'Mailing Address' is not pulled down from the Account level. That lack of that mailing address prevents the system from identifying the potential duplicate. Even custom Matching Rules that try to match on 'Contact.Account' are affected. 

Workarounds available for Contact Matching Rule failures in Lightning

1. Create a Custom Matching rule on Contacts that omits the reference to 'Contact.Account.'
2. Instruct Lightning Users to create new Contacts by using the 'Contacts' Related List on an Account record. This will ensure the Mailing Address is populated and the original matching rules will catch duplicates.
3. Manually ensure the Contact 'Mailing Address' is populated if Contacts are created in Lightning Experience outside of the related lists.

Note: The Product Team is working to document this gap and will be considering addressing this in a future release.