sum of Invoice and conversion rate variances exceeds limit

But the thing is here Invoices conversion rate varies with PO conversion rate in few cases. For example Invoice creation date is 11/20/2022 and the PO applied and PO conversion date is 01/21/2023. In this case because of different conversion dates from Invoice to PO the exchange limit is exceeding the custom Tolerance limit which was fixed. so in this case can we suggest client as to increase the Tolerance amount or any other way to avoid this kind of holds