MIRO Issue

Dears, My clients business is to import goods and trade in local market, we have a scenario wherein we have a PO with 200 line items in USD and have planed cost (freight, customs etc) . We have received material and we have posted GR. We had planned USD 990 for clearing agent in PO, now he has given us the invoice of USD 1000, when we put USD 10 in unplanned cost, system is stopping to post invoice neither it is distributing automatically for all 200 line items. Balance is not equal to zero: 10.29 USD Message no. M8186 Could you please help us in this regard at the earliest. Thanks, Lokesh