Hi Jay Manarang,
As you mentioned, it's a clean server.
Looking at the error it seems BACPAC copy is not transactionally consistent.
While exporting the database have you followed below steps and consideration.
For an export to be transactionally consistent, you must ensure either that no write activity is occurring during the export, or that you are exporting from a transactionally consistent copy of your database.
Reference document - https://learn.microsoft.com/en-us/azure/azure-sql/database/database-export?view=azuresql#considerations
Thank you!