Behaviour of task bar icon

Before I upgraded Libre Office to, when I clicked on the icon in the side bar it would bring the focus to the most recent of any open documents, where these were hidden by other open applications. Now it always launches a new document. Is there any way to change the behaviour of the icon to call up any open documents first rather than create a new one every time, or alternatively, is there another icon I can add to the side bar that will do this, and if so, where is it?

If the behaviour has changed, what is the simplest way to find a LibreOffice document or documents that might be buried several layers deep on your screen?

What is your OS and your desktop manager?