I figured out that the are coming from the Striking – Advanced – Archive Title Settings, Custom Post Type Archive Feature Header Text. My concern is that I have changed something that has impact somewhere else.
The website is: niia.org . The shop page is niia.org/niia-registration-courses
And I also found out that Related Products will show up if you use the same category for different products. This is annoying because now I have to have different categories for each item.