Hello,

Please, send us your website link so we can check the categories problem.

As for the HTML Block in menu, we suggest you to watch our video tutorial to understand how to create mega menu properly https://www.youtube.com/watch?v=fWUe8wPLG2g

If you want to create brands filters, you can use our WOODMART WooCommerce Layered Nav widget in Appearance -> Widgets. There, you just need to add it to the filters area or to the shop page sidebar and choose your brands attribute.

Regards