The do_shortcode() comes out of something else, and it works for the other fields. But, i have got the field which gave the problem also fixed.
The solution was this:
$terms_coach_thema = get_field('coach_thema');
if( $terms_coach_thema ):
foreach( $terms_coach_thema as $term_coach_thema ):
echo '<li class="werkgebied-item">';
echo esc_html( $term_coach_thema->name );
echo '</li>';
endforeach;
endif;
So this topic can be closed.
