Trying to finalize a select flight itinerary, getting error gds-20002

[granade]

I've been able to book in the past without issue, nothing has changed. this is the issue I see:

An error has occurred with your booking. Start a new search and try again.

Error Code: gds-20002

Correlation ID: 46a9d6c2-8cf3-440a-95a9-f04621b33727