The common reason that an order has been marked as Fraud and eventually cancelled by the Fraud Protection System due to your registered address has not matched with the GEO IP address information. For example, your have a Singapore Registered Address but you have placed an order from Indonesia.
However, There are many other reasons why an order could have been marked as fraud and not limited to the above. Unfortunately we are not able to provide reasons and it's beyond our knowledge at most time.
If your order has been marked as fraud and you wish to discuss it, please open a ticket to Sales and our team will discuss what we will need from you in order to proceed.