I'm currently using 125% scale, which I started using recently due to a new monitor. This was also happening to me back when I had it at 100%.
EDIT: I should also mention that I'm using a triple monitor setup, and this only happens on the main monitor, not the other two. I suspect it could have something to do with the fact that I have pinned apps on the main monitor taskbar.
EDIT 2: I was just messing around with the taskbar settings in Start11 and clicked "Restart explorer", after explorer came back it seems to be working now. Let's hope it sticks.