Browser horizontal scrollbar appears when using owl-carousel

On my demo site, i am using the owl-carousel to slide some gallery images.

My problem is, that the browser's scrollbar is always visible, since i have added the owl-carousel to the site.

I tryed deleting html elements, like owl-dots in the console, overflow:hidden on each element, but nothing helped.

Demo site is here:

The owl carousel is almost at the and of the page, under a "Tekintse meg képgalériánkat" title.

It's not the carousel. You are not implementing bootstrap's grid layout properly. https://getbootstrap.com/docs/4.0/layout/grid/

The error is in the row displaying the text "Tekintse meg képgalériánkat".

Instead of

<section class="my-5">
    <div class="row">
        <div class="col">
            <div class="module-head">
                <div class="module-head-title">Tekintse meg képgalériánkat</div>
            </div>
        </div>

. . .

Do

<section class="my-5">
    <div class="container">
       <div class="row">
           <div class="col">
               <div class="module-head">
                   <div class="module-head-title">Tekintse meg képgalériánkat   </div>
               </div>
           </div>
       </div>
     </div>
. . .