Azure function can't access storage account

Hello Mirko Krajcer,

It looks like the difference in behavior comes from how the Function App is being authenticated depending on whether you run it manually vs. when it runs on a schedule.

• Manual run: The function might be using your user identity (with your Azure AD permissions), which likely has access to the storage container.
• Scheduled run (timer trigger): The function runs under the Function App’s identity (either the system-assigned managed identity or connection string credentials). If that identity does not have permissions to the storage account/container, you’ll see the authorization error.

Recommendations:

• Check if your Function App is using a Managed Identity.
  • If yes, go to your Storage Account → Access Control (IAM) and assign the role Storage Blob Data Contributor (or the least privileged role needed) to that Function App’s managed identity.
• If you’re using connection strings / SAS tokens, make sure the scheduled execution is picking up the right configuration (via Application Settings in the Function App).
• Verify that AzureWebJobsStorage and any other storage connection settings are correct in the Function App configuration.

Hello Mirko Krajcer,

Just checking in to see if you've had a chance to review my previous response and let me know if you have any additional questions.

Hello Mirko Krajcer,

I wanted to follow up to see if you’ve had an opportunity to look over my earlier response. Please let me know if you have any further questions.