I came across this same problem but not related to the Qt platform, it is happening with Cocos2Dx. I just wanted to post that it is not a Qt problem, to do with adding to many UI components at once, etc., it's some of kind OpenGL problem which seems to be only affecting some Samsung devices like the Tab 4. You correctly noted that your app is stalling when loading the shared libraries (.so files) for OpenGL.
If I find out how to fix it I'll post here.