I have a parent category with 2 children and I have assigned a menu item to the parent category. I expected that when you view any of the child categories the parent menu would be selected. But instead, no menu is showing as selected.

Is this working as intended?

It basically means that child categories are menu less, even though their parent has a menu assigned.

I'm using Joomla 3 and the latest version of K2

To answer my own question, this was caused by having menu items in a sidebar menu which pointed to the child categories. The path for these was being used rather than the path which included the parent category.