To others who have troubles with repeater fields in flexible content
<?php //Flexible content
if( have_rows('builder') ) :
while ( have_rows('builder') ) : the_row();
if( get_row_layout() == 'shortcuts' ):
//Have to make the count before "have_rows"
//else it will return false
$count = count( get_sub_field('buttons') );
//Repeater field
if( have_rows('buttons') ) :
while ( have_rows('buttons') ) : the_row();
endwhile;
endif;
endif;
endwhile;
endif;