Ionic 3 ios not splash image not applied

as you can see above…I added almost all image to images.xcassets folder on xcode…(I also did it on resources folder on ionic directory…)
but it only appeared default ionic splash image…

so…I added on LaunchStoryboard but it is shown really weirdly on my phone like stretched one.

first question is that just adding image to LaunchImage on images.xcassets on xcode should work isn’t it?

second question is that at least it is shown image by adding image on LaunchStoryboard…
but what is really weird is that
when I launch app , it shows default image for 0.5~1sec (but without loading spinner) then show splash image.