I'm not firm with SUSE or KDE which is the window manager I think.
But there should be ways to move a window even when its title bar is out of screen.
For my Linux I can use the ALT key with left mouse button to drag any window.
Or with a right click on the task bar I get a context menu, where I can select move window to relocate it with the mouse.
If nothing helps, you can search for LibreCAD.conf, which is usually in ~/.config/LibreCAD/.
Open it when LibreCAD is closed, with any text editor.
Find the section
[Geometry] and change the values for keys
WindowX,
WindowY,
WindowHight or
WindowWidth to fit your screen.
Save the conf file and start LibreCAD again.
investing less than half an hour into Search function can save hours or days of waiting for a solution