Apple Hide My Emails not delivering to AWS Workmail

I have several Apple “Hide My Email” relay emails set up to deliver to my AWS Workmail account. The relay emails have worked flawlessly for months. But this week they stopped delivering. If I change my Apple settings to deliver the relay emails to a non-AWS email account they work perfectly. But they will no longer deliver to my AWS Workmail account. I’ve checked my junk folder, deleted folder, etc. and they are nowhere to be found. Any ideas why this would stop working all of a sudden after months of successful operation? Thanks (PS: I talked with Apple support and the issue does not appear to be on their end - evidenced by the fact that the relay emails deliver to non-AWS accounts.)