Move SQL Server database files to Azure storage account container

I'm trying to move SQL Server database files into an Azure storage account container. Creating or restoring databases in container storage works flawlessly, but moving fails. First, I create a credential with the SAS token (permissions: rwdl):

CREATE CREDENTIAL [https://foobar.blob.core.windows.net/databases]  
WITH IDENTITY='SHARED ACCESS SIGNATURE', SECRET = 'secretsecretsecret'

After that I'm altering the existing database and point the both data and log file to the storage account:

ALTER DATABASE [AdventureWorks] MODIFY FILE 
( NAME = AdventureWorks, FILENAME = 
'https://foobar.blob.core.windows.net/databases/AdventureWorks.mdf ');  

ALTER DATABASE [AdventureWorks] 
MODIFY FILE ( NAME = AdventureWorks_log, FILENAME = 
'https://foobar.blob.core.windows.net/databases/AdventureWorks.ldf ');

After I copied the MDF and LOG file to the

container, I restart the database:

ALTER DATABASE [AdventureWorks] SET OFFLINE WITH ROLLBACK IMMEDIATE;    

ALTER DATABASE [AdventureWorks] SET ONLINE;

But I'm getting this error:

Msg 5181, Level 16, State 5, Line 8

Could not restart database "AdventureWorks". Reverting to the previous status.

Msg 5069, Level 16, State 1, Line 8

ALTER DATABASE statement failed.

However, if I'm creating a new database and point the files to the storage account, it works:

CREATE DATABASE [WorkingAdventure] ON PRIMARY 
( NAME = N'WorkingAdventure', FILENAME =
 N'https://foobar.blob.core.windows.net/databases/WorkingAdventure.mdf ', 
SIZE = 1GB, MAXSIZE = UNLIMITED, FILEGROWTH = 50MB) 
LOG ON 
( NAME = N'WorkingAdventure_log', FILENAME =
 N'https://foobar.blob.core.windows.net/databases/WorkingAdventure.ldf ', 
SIZE = 2MB, MAXSIZE = 250MB, FILEGROWTH = 1MB)

Restoring a backup works, too. I'm trying to avoid creating a backup from the databases and restore them into a storage account, because of the database sizes (in total about 20TB).