Icon Theme 6.6.3 - Variants suddenly not working

[avasi3006]

Recently around the 1st of December my variants have stopped working. Customers are unable to select their wig sizes or any other variants accordingly. When I change themes, it works. I haven't changed anything, it's been a sudden stop. The theme I currently use in the Icon theme. Can someone please help as this is affecting my sales. 

Website: www.avasihair.com