I have been facing this black screen issue on mobile device for now almost 4 months from Unity 2017 to upgrading to every version till current date which is Unity 2018.4.
Problem:
1) out of 20 attempts of launching app Black Screen comes for 3 to 4 times on Android Devices(varying on devices) just after Unity Splash and then not even my first scene's awake is called. No exception, just few Unity logs as shown in screenshot.
2) rest of time app launches and everything works as expected but After unity's own splash there is black screen delay for 4 to 5 seconds and after that my first scene launches.
Findings Till Now
As I have been using firebase, facebook sdk, google play games and unity's inapp for my game what I found was that after removing facebook sdk and google play games no. 2 problem got bit better and black screen delay minimized to 1 sec.
Plugins in my project:
Ad Mob, FB SDK, Firebase, Google Play Games. Also Ionic Zipper and newton soft.
Test Cases on Samsung S6 SM-G920F
Complete Project = 4 sec of back screen after unity splash from App Icon Tap to game's first scene. (20 % Stuck on black screen)
Complete Project with just empty scene = same as above
Complete Project without FB SDK and GPG = After splash black screen reduced to 1 sec and no black screen stuck
(Above test cases were run almost 30 times each)
Green is when App gets stuck after splash on black screen and red is when it launches with some delay of black screen.
