I’ve moved
update_field( $field_key, $data, $post_id );
update_sub_field( array($field_key, 1, $sub_field_key), $subdata, $post_id );
Underneath:
update_field
I just set the count to 1 so it’s added ALL cell data except from the first row to the child repeater field of the first parent repeater row. Slight progress!!
I now need to add the correct data to the $subdata
variable.