As per the course, the data transfer between the regions in the billing zone is free. But when I checked Azure portal it says any data transfer between regions is charged. Please clarify..
Data transfer between regions will always be charged for sure. Data transfer within the same Availability Zone is free of charge. Data transfer between Availability Zones is free of charge until Feb-01-2021.
For accurate information about billing of data transfer, you can check the Pricing – Bandwidth page of Azure.
Notice that the information recorded in the course might not be up-to-date, and it’s always recommended to cross-check between the course and the official documentations/website.