Unreal Engine 4.11 - Mirror Mode Can't Go Fullscreen

As described in title, mirror mode in UE 4.11 can’t be set on fullscreen using standalone. I’m using HTC Vive and I tried every possible way from other topics but they failed including: changing values in DefaultEditor file, setting commands like “fullscreen” or “stereo on”, interfering in engine’s source code. Does someone have any idea how to fix this issue?