Wordpress User Exists with Same Email Error

A user is getting the message:

A Wordpress User Exists with the Same Email Address used for Patreon.

When trying to connect their Patreon. I can find no other such account, but there are several accounts that are patron_[longNumberString] that have no email address listed. Is there any way to take that number in their username and find them in my relationship manger on Patreon or otherwise identify them?

This happens when a WP user with an email same with the Patreon user exists, but user’s Patreon email is not verified. Then it is not safe to link the Patreon account and log the user into WP.

In this case, the user must first log in to his/her WP account via WP user/pass, then must connect the account to Patreon via unlock or login flow.