Issue has been magically self resolved, thank you. 

Hi ​@Manu, welcome to the Box Community! I'm sorry to hear that you initially encountered issues with Microsoft PowerPoint Online Archives.

There haven’t been any reported issues on Box’s end regarding this, so it seems like it could have been related to updates on Microsoft's side. I'm glad to hear that the issue has been resolved for now.

Please feel free to continue monitoring this, and if you experience the same issue again, I would recommend reaching out to the Microsoft support team for further assistance.

Have a great day ahead!