Sharing update on linkedin doesn't scrape/pull page title and content

I am working on a website and we have a requirement for allowing our clients to share their pages on LinkedIn.

We have implemented a share button using AddThis which seems to work fine for LinkedIn, but manually sharing any of the pages that work fine with LinkedIn (via the Share Update functionality of our accounts) doesn't seem to work as expected.

When manually sharing a link, the link to the page is properly generated, however the title and descriptive text of the page (we're talking about news articles) are not filled all of the time.

It seems that most of the time we are getting the 404 page's title and content, and sometimes just the 404 page's title and the targeted page's content.

Has anyone else encountered this issue? If so, could you tell me where the information is pulled from and how?