We need to clarify the region restriction in Azure policy applied to resource group since we're encountering a discrepancy in the parameters in the Azure policy when creating a Billing policy in Power Platform Admin Center.

The environment we're trying to add is located in [Australia Southeast], and the resource group is under policy which allows creation of resources in [Australia East] and [Australia Southeast]. Technically, this should pass because the location meets the requirements of the policy.

However, the Azure policy return the error missing region [Australia]. And only when user add [Australia] to the policy, it will allow the creation of Biling policy for the environment which is located in [Australia Southeast].

This doesn't make sense this this mean it will allow all region in Australia and is not restricted to Australia East and Southeast. There is no documentation mentioned this part, so this doesn't make sense to the end users.

We will need a documentation or explanation for this type of scenario to avoid confusion in the future.