Thumbnail isn't showing when i paste the link even on what's app?

My thumbnail isn’t showing when i copy and paste the link. It only shows the typeform one. I’ve tried everything and wanted to send this out today as its already late. I’ve paid for a basic plan which i thought would cover my basic needs (this being one of them) It’s allowing me to change the thumbnail but, the issue comes when i come and paste. Please can you help as it looks really unprofessional with the typeform generic thumbnail. Thanks