Try hovering the mouse over the browser icon in your taskbar, and right-clicking the preview of the Bitwarden pop-out window (as shown in the screen shots above). In the context menu, select “Move”, and then press an arrow key (e.g., ↓) just once, after which you should be able to move the pop-out window with your mouse (do not click any mouse buttons until you are ready to release the window position).