GetViewPortSize issue on iPad air2

[anonymous_user_1521166e]

I have set the r.mobilecontentScalefactor to 1.5 on iPadAir2,and I create the node GetViewPortSize in the BeginPlay in the playercontroller blueprint.When I run the game on iPad Air2,the return of the node:GetViewPortSize are both 0.So I cannot apply the DPI Scale correctly if I set r.mobilecontentScalefactor not to 0.
Maybe a bug?Thanks!