I am absolutely new to linux and started with elementary on a HP probook just now. I am amazed by the easy installation process and the look and handling of elementary. Congratulations! I now wanted to join a second monitor, connection no problem, but the presentation on the second screen was too big. Then I tried different modes in monitor setting and quickly ended up with "eingebaute Anzeige" or "inbuilt monitor", which I can not reset to the original settings. If I undo the connection, I do have the original presentation on my notebook. If I join the external monitor I end up with a very big presentation, too big for the monitor on both items. But there is no chance to go back to different monitor-setting within the settings on my notebook. The Scaling factor is LoDPI. Thanks for an answer and happy new year!