Incident Postmortem from GBL Settlement Team.
GBL believes it was an internal issue on their servers between their Secure Gateway that customers connect to and the Application Core that runs it, it impacted their Secure Gateway ports becoming unavailable.
GBL monitors for issues and their 24/7 staff contacted GBL Settlement Team Sunday night around 23:30 EDT about this and resolved with ports responding again around 00:00 EDT.