Vlookup Not pulling correct info

I have been using the attached workbook for months with no issues. All of a sudden the formula on the second tab (invoices) is returning the correct Contractor in column H. I have =IF(B2=0," ",VLOOKUP(B2,'ODP LISTING'!B$4:J$46,9)). I am trying to get it so that the column looks back to the first tab of the workbook (ODP Listing) and pulls the name of the contract listed in column J based on the matching ODP PO # entered. Normally this workbook is protected so that my users only enter the ODP PO #, the invoice amt, and the taxable and nontaxable amounts on the invoices tab and the rest pulls over from the ODP listing tab.

Any help would be greatly appreciated.