Google is not showing the title in the serps correctly.

Hello,

Thank you for contacting Rank Math support today and bringing your concern to our attention.

We checked the affected site and it seems the title is added properly as you can see in the screenshot here:

Please note that it is a pretty common thing with Google these days. It happens with 70% of the results that even if everything’s fine, Google decides to show a different meta title for your search keyword, there is nothing you can do as Google sometimes ignores the custom meta info altogether and show something from the page’s content that matches the search intent better.

You can refer to this guide for more information:
https://rankmath.com/kb/different-meta-title-and-description/

Looking forward to helping you with this one.