I am not able to find what element is creating the unintended overflow.
Even this CSS which is the general patch to correct it doesn’t work:
html, body {
overflow-x: hidden;
}
But there are is a lot of Javascript related to different adverts that are all manipulating the DOM – any of which could be causing the issue. There are also a lot of JS related errors in the console.
You should resolve the JS errors and then try disabling some of the adverts temporarily to see if any of them are affecting the layout.