Upload PDF file blocked by Fortigate IPS

[rab]

We are testing a new web application to allow people to register and upload a resume/CV, however uploading PDF file is dropped by Fortigate IPS, the attack identified as TCP.Overlapping.Fragments, and the browser displayed "Connection was reset". The filesize that we tested was below 2MB.

Is there a workaround to resolve this issue?

Thank you.