I have had this website for over 3 years and somehow, right now when I try to click on different prices of product variants, they don’t get changed, unless I refresh the page. Not sure why it’s happening…It just started.
Generally it’s down to a JavaScript error on the page. If you know a little bit of web development take a look at your browsers web console and see what errors are showing. That could give you clues as to what the problem might be.
Without a live example to see however the forum members here won’t be able to do much to help. That guess above is about as much as I could do.