Office.context.mailbox.item.getAttachmentContentAsync doesn't return correct base64 format for XML files

Version You have Microsoft Outlook Version 1.2024.403.300 (Production).

Client Version is 20240412005.11 .

Expected behavior

It should return correct base64 format for XML files

Current behavior

When adding XML file through Office.context.mailbox.item.addFileAttachmentFromBase64Async and later on trying to get XML file with Office.context.mailbox.item.getAttachmentContentAsync instead of correct base64 format it returns:

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In older version of outlook (Version 2403 Build 16.0.17425.20176 64-bit ) this works fine, but in newer version it output code above

Steps to reproduce

Open custom outlook add in
Add XML file trough Office.context.mailbox.item.addFileAttachmentFromBase64Async
Go to drafts and open draft message and call Office.context.mailbox.item.getAttachmentContentAsync with ID of base64 file

Context

Worked fine a month ago

OfficeDev / office-js