The usual case here with this issue is that the POS system was not Cashiered In at the time the order was submitted.
If the Aldelo POS terminal where the integration is installed is not cashed in, the orders will not show as prepaid, and show a balance that must be tendered.
The easiest way to tell is by looking at the main dashboard of Aldelo and seeing whether or not the "Cashier In" button is grayed out. If it is not, then the register is not cashiered in.