hi @t24334612,
Can you please provide us your Website url so that we can figure out the issue regarding the sidebar.
The script you added on your site might have affected the sidebar height so it goes under the article. We have coded the sidebar to be sticky so in initial it traces the height of sidebar but here the script you added might have rendered its element’s height later which affects the sidebar height.
And sorry you can’t set the different option for PC and mobile. You want to show last article on mobile. Do you mean the latest article rather than the post by category or the only single last post of the sections or widgets. Please clarify it in more better way.
Thanks