Albeit, when I do…
update_field('categories_sector', 'My Value', $org_id_prefixed);
… I am now getting the following …
Warning: Invalid argument supplied for foreach() in /home/myfolder/public_html/wp-content/plugins/advanced-custom-fields-pro/includes/fields/class-acf-field-checkbox.php on line 490
But only when “Save Custom” for the Checkbox named “Sector” is switched ON.
