I set up my laptop entirely with dual monitors. Never used it with single, until today, when I needed to use it in a separate location. First, when I boot, the login screen (Usually showing up only on my secondary monitor) didn’t show up at all. I managed to log in my typing in my password and hitting enter. Then, my background was completely black, and I couldn’t select anything, see desktop icons, or change my background. I also couldn’t access the right click menu. I assume this has something to do with lattedock, or something. (I use KDE)
Edit: If I plug my monitor back in, it goes back to normal (Without restarting). If I unplug it again from there it works just fine.