Magento 1: Wrong Fedex request sent

I have using magento 1 and notice that when large size of packages request sent to fedex then this request is devide in two small packages like if total weight is 250 Lb then request is sent with weight of 125 + 125 so it means two request sent.
but right now its only sent first request of 125 LB and second request not sent by magento.

so that’s why its also showing a wrong rate from fedex.

Any idea please share.