Multitasking not working

[Fnandlm]

My overview button doesn't work; it will light up and vibrate but it won't trigger the app switcher. I've had lollipop for about a month now, and it only started happening this week. When I restart my device, it's fine for a while until it stops working again. Anyone else having this problem or have a solution?

 

[Golfdriver97]

Have you cleared the cache in recovery or done a reset after the update?