I got really confused about documentation.
In here: https://developer3.oculus.com/documentation/game-engines/latest/concepts/unreal-multi-view/
It says that Multi-View for Mobile only works with OpenGL ES 2.0, and that the 3.1 must be NOT selected.
On Unreal Editor it says that to make Multi-View work you must select Open GL ES 3.1.
The last update for Unreal (4.16-Preview 1) it has on the Release Notes:"The mobile multiview path now supports GearVR."
That means that it never worked? It was working on the branch from Oculus? Which OpenGL we should use?