REF: Child theme Algibro shop – front page parallel effect is not working no mor

I am using a child theme of Azera called Algibro shop. the theme comes with a front page parallel effect feature. It was working perfectly early this week, but suddenly it is not working no more. The first layer and second layer images are both gone, but only leave a dull grey area there. I thought it might be due the upgrade? so i reverted the wordpress from 4.7 to 4.6 but still not working. Could anyone tell me what this happened? maybe Azera theme update breaks it?? Thanks.