Images not showing up in wordpress links when shared to other websites

I’ve been trying to post links of our company blog to our company social pages, but when I do, a gray icon shows up instead of the featured image. We have both featured images and images placed in the actual content of the blog, so there’s definitely enough pictures for other sites to pull. It’s negatively affecting our click rates and I’ve tried everything I can think of. Could someone please point me in the right direction? Thank you!