Hello,
Thank you for contacting Rank Math, and sorry for any inconvenience caused.
Could you please share the affected URLs?
However, please note that Google will not necessarily show the snippets, though, they check a few things first and may choose not to show, for instance, they check the overall quality of the site, and if the snippet content is representative of the main content of the page or not.
I hope this helps. Looking forward to helping you.
Hello,
Thank you for following up.
I’ve checked your site, and it seems that the meta title and description are already set. You can also use this tool for the same as well: https://www.heymeta.com/
If it matches your settings, then you must check if Google has seen the changes already or not.
For that, please check when the Google cache was updated for that page:
a. 
b. 
If the cache date is from before adding the new meta description, then you just have to wait for Google to re-crawl and re-index the page with the new info. If the date is after you made the changes, then you just have to wait it out and there is no further input needed from your end.
I hope that helps. Thank you, and please don’t hesitate to contact us if you need further assistance.
Hello,
Glad that helped.
Please feel free to reach out to us again in case you need any other assistance.
We are here to help.
Thank you.