Runway collection sort order bug

After reordering collection items everything is correct, but adding a new item after this will create the correct _order value, but it is not correctly sorted on the output.

Easiest way to show it, is to show that the actual SQL query being ran doesn't show the items correctly sorted.

SQL query on:

perch_collection('Bilkampanjer', array(
                    'template'=>'kampanjer-listevisning.html',
                    'filter' => $filters,
                    'sort' => '_order',
                    'sort-order' => 'asc',
                ));

SELECT * FROM ( SELECT idx.itemID, ci.collectionID, ci.itemJSON, idx2.indexValue as sortval FROM perch3_collection_index idx JOIN perch3_collection_items ci ON idx.itemID=ci.itemID AND idx.itemRev=ci.itemRev AND idx.collectionID=ci.collectionID JOIN perch3_collection_revisions cr ON idx.itemID=cr.itemID AND idx.itemRev=cr.itemRev AND idx.collectionID=ci.collectionID JOIN perch3_collection_index idx2 ON idx.itemID=idx2.itemID AND idx.itemRev=idx2.itemRev AND idx2.indexKey='_order' WHERE (idx.collectionID=4) AND ((idx.indexKey='endDate' AND idx.indexValue >= '2018-02-01') OR (idx.indexKey='startDate' AND idx.indexValue <= '2018-02-01') OR (idx.indexKey='visKampanjePaaKampanjeside' AND idx.indexValue='vis')) AND idx.itemID=idx2.itemID AND idx.itemRev=idx2.itemRev ) as tbl GROUP BY itemID, itemJSON, sortval HAVING count(*)=3 ORDER BY sortval ASC

See in the picture how it doesnt follow the sortval.