Hello Elena, I believe this video explains what you need to know. 

https://www.outsystems.com/learn/lesson/1136/javascript-in-mobile-and-reactive-applications

Let me know if it was useful, otherwise, I will look for an example.

Hi folks,

I am also facing the same behavior in OS11 - Reactive app. The video Huarlem provided, while interesting, is 4 years old and covers many topics. It is counterintuitive that navigating to a screen for the first time would load the page partially scrolled. This suggests two things. First that there is a mechanism that sets the page in the middle similar to the old bookmarks/anchors. Second that there is a mechanism that is persisting position info between the origin and destination screens. I can't find where I have goofed...probably because I don't understand how the two things work. Any education most welcome!

<script> 
var element = document.getElementById($parameters.Classname);

element.scrollIntoView();
element.scrollIntoView(false);
element.scrollIntoView({block: "end"});
element.scrollIntoView({behavior: "smooth", block: "end", inline: "nearest"});
</script>

// from: https://developer.mozilla.org/de/docs/Web/API/Element/scrollIntoView //

I used the ID of the Page-Title "b1-Title" as value of the inputvariable "Classname".

For value input of "classname" you can use any "name" (=id) of any div-container on the website.