Scroll down to Facebook DIV or Load conversations without scrolling down

I'm trying to scroll down the conversations of My Public Messenger's Messenger page down.

To using the following code (Injecting through the Google Chrome Console)

var divt = document.getElementsByClassName('_24tx');
    var x = divt[0];
    x.scrollHeight = 374;

The value of x.scrollHeight before code: 433 The value of x.scrollHeight after running code: 433

But if I manually lower the value of x.scrollHeight it will change!

I'm trying to set up a script to filter my conversations, but the conversations will only load as the scroll scrolls down, if anyone knows how I load the rest of the conversations without having to download my scoll it also solves it!