VR mode fail when I use UE4.12.5,HTC VIVE and open dedicated server

Development Platform & Builds XR Development
1

Hello, I use UE4.12.5 HTC VIVE but when I open dedivated server,the rendering is error .I think it just one eye rendering .because FPS is more than 160 .Please tell me how to solve it ?
If I do not open dedivated server ,all thing is ok !