underscore template dynamically remove row Jquery

This isn’t WP related but Its not working because you are trying to add an event to a dynamically created element.

Replace…

jQuery( '.remove_field' ).on("click", function(e){ 
    e.preventDefault(); jQuery(this).parent('div').remove();
});

With

jQuery( 'body' ).on("click", '.remove_field', function(e){ 
    e.preventDefault(); jQuery(this).parent('div').remove();
});

You can read more about your issue here.