Problem downloading attachment in Outlook Web

Question

Hi,

In our company we use Graph API to get outlook messages (search API). Using the webLink the API provides we redirect the user to OWA Outlook to show the selected message.

The problem comes when the user tries to download an attachment, instead of downloading the attachment it downloads an HTML with an Outlook envelope animation with the name &isDownload=true&animation=true.htm (see picture below). What is the cause? Are we missing something?

The link we navigate to is: https://outlook.office365.com/mail/deeplink?ItemID=XYZ&exvsurl=1&viewmodel=ReadMessageItem

Thanks!