I have a requirement wherein I have to make a callout upon Pageload. 
The continuation request method is getting invoked, but not the callback.
The response is not getting displayed.

Steps to replicate the same:
1) I'm calling a controller method from action attribute of <apex:page> 
2) From that method I'm calling the continuation method.
3) For some reason, But the call back method is not getting invoked.

PS: The same thing is working if I call from a command button with render attribue

Any help/pointers would be highly appreciated.
Many Thanks!