Gorpal said in a comment
Please make sure you are using right names and size of splash screen. Default-Portrait~ipad.png -- 768 x 1004 Default-Portrait@2x~ipad.png - 1536 x 2008 Default~iphone.png - 240x 320 Default@2x~iphone.png - 640x960 Default-568h@2x~iphone.png - 640x1136
which worked for me. It's all about the correct name.