Use the cursor to select one or a range of transactions in you Wizard worksheet, making sure you have included the first line of each transaction. You can also select a non-continuous range using Crtl+click to select the desired transactions.
AR Invoice Wizard looks through the Wizard only between the top and bottom of the range you have indicated.
If you have selected a range and only included the first line of the last transaction, AR Invoice Wizard will continue past the end of the selected range if necessary to complete the last transaction.