Timing gate course discrepancy

I have a race this weekend, Monumental half marathon. 

I added the race into Connect and the "official" course downloaded to my watch. 

The weird thing is when I added the race, which Connect said was an official race complete with timing gates, the distance said 13.11mi, however the official course shows as 13.31mi.

I've ran this course several times and it ranges from 13.13-13.3mi.

Not sure why there's a discrepancy between the race distance and the official course. 

A company called Ahotu is listed as the company that provided the official event to Garmin, but it seems like the course should be 13.11mi.

Hopefully someone can weigh in on how these courses are obtained. I'd love to try this feature but it's also worrisome seeing the discrepancy.