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Do you also use macros to execute workflows?
Can you provide detailed steps that you add to a task?
Based on my tests, I can display and open attachments normally after I add a message with attachments to a task. Below is a screenshot of what I added as a task. After you add to a task, the attachment appears as plain text, and then manually inserting the attachment will display it normally.
By the way, Outlook actually has an official feedback portal where customers can send feature requests or suggestions to the product team. I searched there and noticed that similar ideas had been posted and the Outlook team had collected the project. I have added my vote there and I will leave the link below so that you or others can see this topic and also vote or comment there.
Hope this helps!
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