I’m not sure what exactly is happening, but the primary monitor being “disconnected” seems to cause the window to bug out.
When you copile and run the code, it seems to attempt to run the screen on the disconnected main monitor, as if it were working. I say this, because the connected screen looses all functionality but retains an image of the desktop/open windows, like secondary monitors often do when a full-screen app is running.
You have to alt-tab out of the application back to the desktop and manually close the debug session using only the keyboard, if you attempt to use the mouse it says it is loading, infinitely, and you can’t do anything with it.
However, if you run the same code with the main monitor connected, using the second monitor as the selected monitor, it works fine on the second monitor, but even using the second monitor as the base doesn’t work with the main display disconnected.
I know that the code is identical because I’m using an external file to set fullscreen settings, using the GLFWmonitor **monitors = glfwGetMonitors(&count); and array indexing to retrieve the relavent monitors.