Thanks for the answer but it does not work. I am well aware of that switch and now I switched that “ON” on my website which does NOT display category in the breadcrumb. It still does not display the category.
It is OFF on my website which DOES display category in the breadcrumb correctly.
In fact, that switch does not do what I want. As explained under that switch:
“If category is a child category, show all ancestor categories.”
This is not what I want. I want to show the main category in the breadcrumb but somehow I couldn’t do that. Switching that switch on-off changing nothing. As I said above, it is OFF on my site that displays breadcrumbs correctly.