Dropped packets from behind Fortigate

So usually I am on here posting solutions but today I am going to post a problem because I am having trouble finding a solution.

Here is the situation, a network protected by a Fortigate 100A firewall, they can’t reach a website. A tracert to the website shows that the packets are being dropped by a router owned by the local telco. Here is the twist, when we bypass the Fortigate it works fine. Now local telco claims it isn’t there problem (it never is of course, it’s only there router dropping the traffic) and Fortigate claims it’s not there issue (why would it be except of course the issue only occurs when we use their product) and so I have accepted I wil get help from neither of these  … uhm guys. So any suggestions are welcome here.