Google indexing uses content instead of description

I have a page with meta description, but for some reason Google indexing sources its value from the content of the page, and not even from the beginning of the text, but from a sentence in the middle of the paragraph. I've checked the html, but don't see any reason for it. Robots are not affecting this page either. What else could be the reason? Forgot to mention I'm using Umbraco 4.7

The snippet Google shows will generally be related to the query the user has entered. In some cases, this will match well with your meta description, but if there is content elsewhere in the page body that better matches the user's search, then Google will show that part of the page instead.

This article on Moz.com goes in to a bit more detail on how you can gently steer Google in the right direction towards your meta description, but ultimately it's not something you can control.

So, is there anything you can do to bend Google to your will and always use your META descriptions? Unfortunately, the short answer is "no". Like so much of SEO, though, there are some ways to nudge Google in the right direction