@Craig Edmondson For better understanding and clarification: Have you followed the steps mentioned in the perquisites .
Also have you updated the password? Update the password of your storage account identity in AD DS
It typically takes about 15 minutes for an Azure AD DS deployment to complete. Verify that the health status of Azure AD DS shows Running, with password hash synchronization enabled.
There is also similar thread discussion in the MSDN forum, I would recommend once's refer to the suggestion mentioned over-there and let us know the status
Looking forward for your reply!
Hope this helps! Kindly let us know if the above helps or you need further assistance on this issue.
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