So is Unity 5.2.4 unreleased? Did this fix make it into 5.3?

The reason why I think the problem is with Unity is that no other Unity games are doing it. Granted, they may be built using older versions of Unity, but that just proves the point further that Unity can prevent this behavior.

The only workaround that I have found is to force a change in rotation (using Screen.orientation) to something other than the starting/current orientation, then rotate back. Doing this takes at least a few seconds and looks just awful. It is absolutely out of the question for any professional app.

Also occurs with the Nexus 9 (Android 6.0, Unity 5.2.1f1) on every launch after quitting with Application.Quit() or swiping the app from recents while it is the foreground app. Re-installing the app does not work, forcibly stopping the app does not work. Rotating the device to another orientation or minimizing the app fixes it only for that session.

I couldn't seem to find a permanent workaround other than restarting the device completely. My bet is it's a problem with Android 6 and not Unity.

This bug started for me after upgrading to 6.0 marshmallow(Nexus 5). Tried a system reset to make sure it wasn't an anomaly from the upgrade process. Only way for me to get rid of the black bar is to minimize the app then bring it back.

Severity: 3...."workaround is possible"...I have spent days trying to find a workaround. There is no workaround. Please increase the severity, or explain the workaround.

Tested against every version of Unity after 5.1.1f1 (currently on Unity 5.2.1f1) and the bug still occurs. I have my Nexus 5 updated to Android 6.0 (marshmallow) and have Android SDK v21.

Tested this on Unity 5.1.3f1 and the bug is still there.