whatsapp problem

It seems that when the featured photo is auto-generated, when you paste a link to whatsapp, the image is not shown. It must be the size limits imposed by whatsapp?

There is some blurb here: https://roei.stream/2018/11/18/ideal-open-graph-image-size-for-whatsapp-link-share/

The page I need help with: [log in to see the link]