Help with program/smart campaign - some leads went through flow twice

[Mikes_Jones]

A little puzzled.

We sent out an an email to over 10,000 leads yesterday via smart campaign tied to a program (which is tied to a SFDC campaign).

The smart campaign was scheduled to reoccur today, and it was supposed to affect around 26 leads, which seemed fine - as there were about 26 new leads added to the Salesforce campaign. However, when the email finally went out it was sent to 26 internal employees, however, these 26 employees already got the email yesterday. Additionally, the new leads that were supposed to get the email did not.

Now, I have the smart campaign set up so that each lead can only run through the flow once, so I have no idea why a small handful of leads went through it twice.

Can anyone provide some insight as to why this could have happened?