Our latest update from GlobalSign:
"Right now the datacentre is stabilizing, however due to big queues of service it will take some time to clear the backlogs.
While this is happening some requests might still not be served (503 error) in order to clear the backlogs in a stabilized way.
This error should gradually reduce and ultimately operations should render normal again."
See current status from GlobalSign here: https://www.globalsign.com/en/status