After unity splash screen and before our first scene is loaded (1-2 seconds window) I sometimes get strange graphical glitch, maybe on every 10 startups. Does anyone have any ideas what might be causing this? I’m attaching a screenshot.
Is there any more suitable thread than this to ask this question?
I meet the same problem.
https://forum.unity3d.com/threads/uptate-to-unity-5-5-1-android-app-broken-screen-after-mwu-logo.456689/
I found the solution, 5.5.1p3 fixed the problem 
Here is the link to the issue: Unity Issue Tracker - [Android] Delay after splash image and distorted background image
That works, Thank you very much!