trigger works with button click but no with document ready

trigger works with button click but no with document ready

I have some checkboxes which trigger an ajax search. I want to check the boxes automatically and trigger the search. If I run the triggers from a button click, it works fine. But if I add them to the initial load function, the checkboxes are checked but the triggers don't work. Why? Here is the code first I uncheck all the boxes.
jQuery( "[id^='radio_']" ).prop('checked', false );

Then I trigger checking certain boxes.

jQuery('#radio_2155').trigger('click'); jQuery('#radio_1775').trigger('click');