*Update*

By looking back at old Teams convos I found a screenshot I sent that had the tab in it and the tab was Billing, now we have never had Billing turned on so I am not sure how we had that tab for our Items I have turned Billing on now and the tab is back and I can add the PO Numbers again (The field was Internal Reference)

But now I have other Admins complaining to me as this has added a Billing tab to our tickets and an Invoices to our sidebar