Post Descriptions when Sharing

Hello Custom Community Support!

I share posts to major social networks, when I share the post, the description is different than the post subject. All of my posts have titles and urls that match the title of the post, so I’m not sure why this is happening.

Selecting an appropriate photo is fine, but when I have to change post descriptions with every share, it’s defeating the purpose of sharing.

What might I do to resolve this issue?
Thanks,
Sherry