I have installed Lubuntu 19 and my default resolution causes a part of the desktop to be eaten, I went to LxQt Settings > monitor settings and changed it but on restart the changes disapear. I read about this bug and a way to fix it but it was about the version 16 and there was an explicit x11/session.d folder in /etc where we needed to add a file but I can't find this folder now.
When in Monitor.Settings, you can press
- "Save" (to save for future sessions)
- "Apply" (test the change but don't save for future)