Created attachment 8874
video of bug
When using multiple applications in a launcher, clicking the arrow pulls up the list of applications. If you click an application, OR click outside the window to hide it, the arrow that brought up the menu remains highlighted. To un-highlight the arrow, you have to mouse over it, then move the cursor away. This is a new problem with 4.14.0. Tested on Arch Linux.
I can reproduce the problem. I'm not sure why the menu_deactivated signal doesn't go through (as it's responsible for rendering the widget inactive), I'll have to check.
Simon Steinbeiss referenced this bugreport in commit 76c10ece7d93dc822bfc20389b17b29b9b70a270
launcher: Fix visual state of arrow-button (Bug #15818)
*** Bug 15862 has been marked as a duplicate of this bug. ***