Blackboard has successfully resolved the issue with their receipting tool. Consequently, students submitting work to a Blackboard Assignment should now receive a confirmation email containing the details of the submitted work and a link to the document.
Please note that the issue only impacted student submissions to Blackboard Assignments on Tuesday, 7 May. Nevertheless, all receipts were securely stored in Blackboard, and students were able to access their submission records by navigating to the Submission Receipts section within My Marks.