I fixed it. For anyone else struggling, ths worked for me:
<?php
if( have_rows('text_area') ) :
while ( have_rows('text_area') ) : the_row();
if( get_row_layout() == 'text' ) :
if(get_sub_field('columns') == "1") : ?>
<div>
<?php the_sub_field('first_column_text') ;?>
</div>
<?php elseif(get_sub_field('columns') == "2") : ?>
<div>
<?php the_sub_field('first_column_text'); ?>
<?php the_sub_field('second_column_text'); ?>
</div>
<?php endif;
endif; //get_row_layout
endwhile; //have_rows
endif; //have_rows
?>
