We are sharing the image and provding the image url via below link https://www.facebook.com/sharer/sharer.php?u=https://certificate.careerera.com/resources/certificate/9VdjSWNUYW4s18k.png

sometimes its works fine shows the exact image but sometimes its black image as shown in attachment. We have already passed the og:url tag in page html.

please look into this issue and suggest on the same.