Difference between 'preview's

I’m tring to improve my site with wix-codes, and found that my new code works when I preview the page via menu bar of editing page, though it doesn’t work when I preview the page via dashboard after saving it. Does anyone have explanation about the difference between two cases ? And can I expect that my new code will work when publish the page ?

There is an issue regarding the dashboard’s Preview and it is currently being worked on.

Thank you so much. I believe my code will work, whether solving the issue takes time or not.