I tried plugging this in to functions.php and set the field value to the post_name field in wp_posts table. That value is field_5b872b6587fbe
I assumed replacing the field in your example was referencing this field from wp_posts.
My admin panel is not doing anything differently when I test it so I figured I’d explain what I did and see if you have feedback.
I should also clarify that I put a die(‘test’); in the set_start_rows function right at the beginning and it did not trigger. looks like the function isnt being called. Could this have a typo or something in it?
add_filter(‘acf/load_value/key=field_5b872b6587fbe’, ‘set_start_rows’, 20, 3);
