My phone suddenly has a new bottom navigation bar that is just three VERY thing horizontal gray bars. The right one if you flick it up goes back, the middle one exits and the left one brings up the running apps.

I really don't like this nav bar and can't find any reference to it anywhere. Does anyone know if this is from an Android update or if this is from some other app and if it can be undone?

One of the things I loved about a recent Android OS update was that I have a few games that used the Menu nav item to reach settings in the game and this update removed that so now they're only partially functional.

I tried using Samsung's GoodLock app (I think it's called NavStar) to override this nav bar, but it simply fails to work leaving these three thing bars.