Hi,
When HikaShop displays the notification blue box, there is a javascript error in the browser console:
i.imgur.com/8VhWWf3.png
This error comes from the jquery easing plugin of jQuery added by the accordion CK module on the page.
I believe the issue comes from there as it prevents HikaShop' javascript from adding the setTimeout to auto close the blue box later on.
Now I'm not sure why. However, even just after I display the page, when I start scrolling the page, I also see that same javascript error on the console log.
So there is apparently something wrong with that jquery easing plugin. I would first recommend to disable temporarily the accordion CK module, clear your website and browser cache and check that you don't have the javascript error anymore, and see if you still have the issue with the notification box.
If you don't get the javascript error anymore but it still doesn't work, then we'll have to investigate. But it's likely that it fixes the problem which means you'll have to check with the developer of that module to fix that javascript error.