Google VR on Android devices Split Screen problem

I am working on a custom made Android device, I have tested my demo Google VR project on Samsung Note4 and Nexus 6P without any problem.

When I deploy my project to my custom device, the screen becomes to small. My device using Qualcomm 820 with Android 6.0.1

I am using Unreal Engine 4.13.1

Has anyone figured out this before? The picture is getting from HDML.

Is this device made by Chinese? Use “adb shell wm size” to change the resolution! They always make trash like that!

Thank you very much, I try to adjust the screen size and finally solve it.