We are legally required to check users against restricted party lists published by governments around the world. If someone is flagged as a potential match, we have to disable their account until we can verify whether or not it was a false positive.
Unfortunately, new restricted party lists are published all the time, which is the reason why someone who previously had access can become blocked. The quickest way to get unblocked is to use the form on the “Access Pending” page (as your tech did, and I believe they were unblocked within a couple of hours).
I’m very sorry for the inconvenience.