[Plugin: WP Parallax Content Slider] Parallax movement not showing in IE9

I have this installed as the homepage scroller using the static slide method. Even if I turn on the post method the parallax movement doesn’t work. The text and images do move from right to left but the background image doesn’t move and the text and image move at the same time instead of independently.

Any suggestions?

https://www.ads-software.com/extend/plugins/wp-parallax-content-slider/