@Terry Chan For better understanding the query: Are you referring to Azure Files Storage?
If you are using Azure File storage you used be using SMB protocol.Store and Access Data in Azure Storage from Xamarin.Forms
This forum is mainly concentrated on Azure-Files Storage.
Based on your scenario I would recommended to post your query in Xamarin Forum File Handling (Android and IOS) or create an issue or ask on the Xamarin Forums.. These forum community members could provide their expert guidance on your scenario based on their experience. Thanks.
Additional information: Based on the error message I want to refer to this SO thread which may give some idea on your issue.
Hope this helps!
Kindly let us know if the above helps or you need further assistance on this issue.
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