Mobile menu: category name not displaying

I have a small display problem with the mobile menu view when I am selecting any product category. The mobile dropdown menu works fine, but the selected category name does not then display on the black menu bar. All normal wordpress pages and actual products display a name as expected. Only the categories (homeware, kitchenware, furniture and fashion) do not display the selected page name. Anybody have an idea how this can be fixed? Site is at: http://www.tiptopvintage.co.uk

Thanks!

https://wordpress.org/plugins/woocommerce/