Help! Help! Google only showing category instead of full post title

I have a wordpress blog with Yoast SEO
When I post a blog, I choose custom permalink

For EX : www . domain .com / post title

But in google search result it shows (for a blog post)

www. domain .com / category

Why? Why its only showing category and not post title in permalink
WhenI click on that it shows the post but why the permalink is different in serp?

I believe this has to do with your breadcrumb settings.

In yoast there are templates for titles, change that specifically in yoast