The default position of the sidebar until recently was on the right. Now it is on the left. How can the default be set to be on the right again? This first happened on 7.24 and is the same on 7.25.
LibreOffice sidebar has always been on the right side, but could also be moved to the left. You can undock the sidebar to drag it to the right by clicking on the three line icon (Sidebar Settings) on top of the sidebar option icons (with the Sidebar on the left, it should be just below the File menu), and choosing Undock. The Sidebar should move to the center of the screen, from where you can drag it with the mouse to the right (a black outline should show the new position).