Escape key no long working in task switcher
Prior to 4.18:
When using the alt-tab key to activate the task switcher overlay, you can keep holding down the alt key, and it will keep the task switcher displayed on the screen. This allows you to pause to look at the list of open windows in the task switcher. You can then resume pressing the tab key to keep cycling through them.
But one other piece of functionality that was allowed here is that, with the alt key still held down, you could press the "escape" key, which would then dismiss the task switcher overlay window completely, without the need for you to select one of the windows in the task switcher and then release the alt key.
This escape key functionality is no longer present in 4.18. When you are holding down the alt key to display the task switcher on the screen, the escape key now does nothing.