This did the trick for me. Probably a perversion (my php skills are very basic), but works
$termss = get_field('collectiona');
$slll = $termss->slug;
$args = array(
'post_type' => 'products',
'product-collections' => $slll,
);
$lineblocks = new WP_Query( $args );
if( $lineblocks->have_posts() ) {
while( $lineblocks->have_posts() ) {
$lineblocks->the_post();
and query reset at the end of every array
<?php wp_reset_query(); ?>