How does "View old POs and resend them" work in Dropshipping module?

Hi everyone, I'm testing Customers>POs - Send/Resend. I just sent out a PO to one SC (myself for testing). Then I hit the button "View old POs and resend them". The order I just sent out doesn't show on the page. Should it list all the POs I sent out to SCs?

In other words, how does this button "View old POs and resend them" work? Does the page show all the POs I sent out to SCs previously after hitting this button? Otherwise, how can I keep track of all the POs I sent out?

Thanks.