Question [Q] android.app.DownloadManager.Request.enqueue callbacks not invoked in Kitkat

Hi,

I am developing a module for which I have hooked android.app.DownloadManager.enqueue callback. The code is like this -
Code:
Unhook hook = findAndHookMethod(android.app.DownloadManager.class,
							"enqueue",
							"android.app.DownloadManager.Request",
		    		new XC_MethodHook() {
	            @Override
	            protected void afterHookedMethod(MethodHookParam param) throws Throwable {
	            	log("After enqueue.");
	            }
});
This code is invoked from initZygote. It was working perfectly fine in Jellybean 4.1.2 on my older Xperia J. However, the callback is not invoked in Xperia Z running Kitkat 4.4.2 ROM. The callback does get attached successfully since the "hook" value is not null. I have tried moving the invoke into handlePackageLoad when the "android" package is loaded, but still no luck.

Any suggestions?