After I update to 4.21 version from 4.20 when I deploy project to Android and launch it, I see the launch image that disappear and screen turs black for a while. When it was 4.20 on launching android app launch image was entire loading, so no black screens.
Any way to fix that?
Have you tried retrieving the logcat from your android device? You might learn what the problem is.
Looks like it was a unreal bug that already fixed in 4.22
https://github.com/EpicGames/UnrealEngine/commit/3202fdd437db76772f36d6d697e2ec5ffab2