Scenecapture2d : material wrong alpha on android

UE 4.20.3 version.

now i tried to render my model to blueprint widget as a image…

and configure scenecapture2d and material, rendertarget texture…

capturecomponent2d capture source is SceneColor(HDR) in RGB, Inv Opacity in A

and one minus - alpha on material

PC platform is okay what i want… but always wrong alpha on android…( black color exactly…)

help me to fix it …