Item image zoom and select not working on items without variants

[MTNOffroadFab]

I’m having an issue that only happens on items without variants. When you hover the mouse over the item main image, the zoom doesn’t work and when you click on the thumbnail images they don’t move to the large image spot like normal. Instead they open on the browser window. 

[MTNOffroadFab]

The theme is Supply. Website is www.mountainoffroadfab.com

[GTLOfficial]

Hello @MTNOffroadFab 
Welcome to Shopify Community

actually the supply theme is no longer avablilabe in shopify
and the problem you told us is that is a custom code part so you need to check your theme code.
If you need our assistance please let me know

Thanks

[MTNOffroadFab]

What I am asking for was a built in feature with the Supply theme. It was a working feature but has stopped working randomly which is why i'm trying to get help.