Order-level sales credit total () must equal 100% error during booking

Hi,

If I place an order direct into Orader Management, I do not get the issue. However, when I place an order for the same customer, with the exact same details, through iStore, I always the get the error Order-level sales credit total () must equal 100%.

The order from iStore always imports as Entered and not Booked due to this issue and all that I have read on it states the reason is due to the Sales Rep not being entered on the sales order. This is not the case as the Salesrep is automatically entered at both header and line level. If I try to book the order immediately, I again get the error/process message and have to do Actions > Sales Credits > add in the details, the order then books as normal.