I used Ubuntu 16.04, but in U18.04, when I use the combination of ALT+F4, it closes all windows along with the background windows until it reaches the desktop screen and no other app is running.
It happens mostly when I use VLC. Also for other apps as well.
Expected behavior: It should close only the current window/app.
Actual behavior: It closes other windows along with the current one.
Is this a bug or my mistake?
I don't press keys for a long time, which could cause closing all windows.