I also had same problem in my website: https://www.projectsatbangalore.com/Mech.html
But Now i had rectified.Follow the the steps,
Scroll down below the text editor until you find the section titled “Yoast SEO”. Edit the information listed under “SEO Title”, “Slug” and “Meta description” until you’re happy with the way it appears. … Double check your “Snippet preview” to make sure your title, slug, and meta description appear the way you intended
