Contact the consulate (via email and follow up via the phone when they reopen ) and see about getting a new stamp and when able have them travel. (highly recommend not to wait until the last minute to travel when the new IV stamp is issued). Good Luck.

They will not be permitted to enter the US for the time being. They will have to wait abroad.

I agree with my colleagues. You need to contact the US embassy or consulate that issued your visa stamp and ask them to issue another visa stamp.

In situations like this one needs to simply contact the US consulate in question, explain the "situation" why is it that they couldn't travel when supposed to within the 6 month mark - here needs no "explanation" other than mentioning "COVID-19", "travel ban" - pay again and ask them to issue another Immigrant Visa stamp for each.

Contact the IV Unit at the consulate and they will react and respond - sooner or later. Keep on "reminding" them every week or so, until get not only "response" but also "action."

Although your form/service center references are a bit incorrect (the I-130 was sent to US CIS and not the NVC) ... I understand your frustration.

You forgot to tell us what Consulate issued their Immigrant Visas.

They won't have to go through the entire process ... but may need to go back to the Consulate for a new IV 'stamp'.

Go ahead and contact the Consulate now. Even though they are probably closed, most of them are responding to e-mail.