See :
https://www.sistrix.com/ask-sistrix...ot-being-displayed-in-the-search-results-why/
It shows you why google not being displayed your own meta description .
Steps to create the good & right meta description ,
Keep it up to 155 characters.
Use active voice and make it actionable.
Include a call-to-action.
Use your focus keyword.
Show specifications, where possible.
Make sure it matches the content of the page.
Make it unique.
See :
https://yoast.com/meta-descriptions/
It shows you more details about above steps .
See :
https://www.webapex.com.au/blog/meta-title-description-seo-guide/
It shows you more details about meta title and description seo guide . It shows you how long does it take for google to update meta title and description , how to get modified meta title and description indexed fast , how to write a good meta title and descriptions , how many keywords should you have in your meta title and description and more .....
Hope this Helps !