I found research about dropping the vertical menu and use a horizontal instead
Dropping the vertical menu had a positive effect products on my site as the specific product became the focus of the page.
The problem is with scrolling - if a customer goes to the bottom of the page and wishes to switch the category he has to scroll up and select an element of the menu.
I am thinking of solving this issue by converting my top menu (that has all the categories, contact info and other cms pages) into a sticky menu that is always shown.
Do you know of research that points out that a horizontal sticky menu is bad UX that damages conversion rate?