I’m going to try to help you by explaining what the problem with your code is. This comes up often because most people don’t understand how wp_reset_post_data() really works.
// this is inside the main WP query loop or "The Loop"
// some time later
$post_object = get_sub_field('pick_the_dates');
if( $post_object ):
$post = $post_object; setup_postdata( $post );
// some time later
if( $venue_object ):
$venue = $venue_object;
setup_postdata( $venue );
// some time later,
// this is the problem.
// wp_reset_post_data does not take any arguments
// this function, no matter how you call it will always
// reset post data to "The Main Query"
// once you do this, any reference to the post
// object returned by get_sub_field('pick_the_dates')
// will be looking at the post of the main query instead
// of what you think you are looking at
// in order to have multiple nestings you must use
// alternate means of getting values
// other than using setup_postdata and wp_reset_postdata
wp_reset_postdata( $venue );
// some time later
// this next line actually does nothing
// because it was already done above
wp_reset_postdata();
