Hi all,
Here is an update of this issue:
This issue has been fixed in Office version 2106. A fix for Office version 2105 will be release at a later date. For more information, please refer to this official document: "The properties of the message have been changed" prompt when forwarding/replying in Outlook.
If it's possible, it's recommended to update your Office to version 2106 to check if the issue has any difference.
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