There are 2 conditions of the Total Due number on the Dashboard Page 

Total Due reflects the amount from the ERP system and the YayPay platform does not influence this amount. 

If you have "Use calculated balance" checkbox on in Business Settings, the Total Due will be calculated by YayPay System: total open balance for all active companies with non-zero AR. 

If you have any additional questions, please contact support@yaypay.com.