Getting vertical and horizontal bars usually depends on the size of the window you are looking at. For example I am writing this with Chrome browser set to its maximum width and if I drag the sides in to decrease the width then a horizontal bar automatically arrives at the bottom of the page so that I can see the edge. What programmes are you using where you feel the need to scroll horizontally? If you decrease the size of the programme window can you see a horizontal bar then?
HTC U12 Plus review: Hands-on