Screen scroll is blocked

This happens because you apparently add fields to the form after the page loads completely. Therefore you must do resize

You can check like this:

height = $(window).height();

When you add data to your already loaded form

if($(window).height() != height){

}

Here check if the current height of your screen is different from the previous one, if this is the case you should update the height

Another way I can think of is to add this css to your class containing the form.

height:100%; overflow:auto;