Hello, @wssrob,
1. Sound’s Good!! that you found the culprit, so I suggest you, please do not use that plugin as that seems to be conflicting with the theme, or contact the plugin Author for further help on this.
2. Now regarding the issue of our Demo site, you are right, I have checked the same demo product and found the issue, but then I imported the same demo on my test site and tried to test the same product with the same demo on my test site and there is no such issue.
So it means the issue is on the Demo site particular product only, we will check it soon and will fix it on our demo site as well.
Thanks for your understanding.
Regards 8Themes Team.