Maryanne, the following MIGHT be the problem.
HSB uses the Sassie platform for report submission. They pay approx. 60 days after your report is RECEIVED, BUT, there is a level between submitted and received: COMPLETED. If, as an example, the shop, submission and completion were on 10/25, BUT, it was not received until 11/03, this usually due to editing concerns, the pay would be due 01/03/25.
I have never read or experienced this MSC stiffing anyone in the 19 years of our association. Payment wise, all I ask of any company with whom I am contracted, is that I am informed of the amount, the method and when. HSB AKA Service Sleuth, has never disappointed.