Hi,
Thank you for getting in touch.
Please edit the title of the post/page and remove that.
You can check your global title settings from WordPress Dashboard > Rank Math > Titles & Meta > Posts.
Once done, please check if your actual SEO title matches the one you have set using Rank Math.
You can confirm the same by opening the post and then following this image tutorial
https://mythemeshop.d.pr/ePhMiA
Once the source is opened, search for the word <title>
and you can confirm if the title is the same as you entered in the plugin.
If it matches as seen in the HTML source code there is nothing to worry about. Google sometimes does not honor your titles and displays them as per their will.
You can go through this post on Google Search Console support section: https://support.google.com/webmasters/answer/35624?hl=en
Specifically, you might want to check the title Why the search result title might differ from the page's <title> tag
Hope that helps and please do not hesitate to let us know if you need our assistance with anything else.
Thank you for your fast and informative reply