portfolio thumbnail does not generate

I have created a portfolio using the gallery schema sort of like the sample in the dummy data.

I loaded up 5 images. The actual portfolio page looks fine. There is a marge image and string of smaller images immediately below.

However there is no thumbnail on the actually portfolio edit page where all portfolios are listed together. And there is no thumbnail in the recent projetcs strip shown at the bottom of the site page. Is this images self generated of am I missing something? The thumbs from the dummy data show up fine.

Thanks,

John