Inline Attachment cannot be retrieved by JSM Customers through API

Issue Summary

When attachment is added as Inline Attachment in Public Comments and JSM Customer (Atlassian Account with no Jira License) not able to download INLINE attachments using REST API Get attachment content.

Customers get below error while using REST API.

{
    "errorMessage": "You do not have permission to view this attachment",
    "i18nErrorMessage": {
        "i18nKey": "sd.attachment.error.cannot.view.attachment",
        "parameters": [
            "10098"
        ]
    }
}

• But Customers can view the Inline attachment from Customer Portal and access it. Only issue is with REST API.
• When using the same API call, Agents can access the attachment but failing for customer users.

Steps to Reproduce

1. Create an Atlassian Account and assign only JSM - Customer Role.
2. Create a ticket with Request Type and add the above created user as Reporter or Request Participant.
3. Add a Public Comment with Inline attachment in it.
4. Use the API Get attachment content. to get the attachment content as the Atlassian Account customer and observe the error.
5. Use the same API call by changing authorization to Agent or Site Admin, works fine.

Expected Results

Inline Attachments should be fetched by API for JSM Customers as well.

Actual Results

Receiving error : You do not have permission to view this attachment

Workaround

Change the Attachment type from INLINE to THUMBNAIL and it works fine for Atlassian Account customer.