I often "lose" my Google Chrome after using it on second monitor. After disconnecting the monitor, I cannot find a way to get Chrome back, other than restarting the system. Closing the app with keybindings, etc does not help. The system obviously thinks that the second monitor is still there.
Wanted monitor: current active monitor only i.e. the laptop monitor
I can reproduce the situation in X11 and Wayland.
OS: Linux Debian Stretch 9.1
Window manager: Gnome 3.22 on X11 and Wayland 1.17