I guess that you are referring to the first widget on the home page of that website.
I’m not sure why it could behave differently earlier, but you can try to edit that SiteOrigin Editor widget, switch to Text tab, and wrap all HTML code there into
<div class="container"> before content, and
</div> after it.
Please remember about importance of regular full site backups (files and database):
Also you might want to check this tutorial:
Kind Regards, Roman.