Please visit below link and read the shopify staff answer.
Please deactivate the cart expire functionality and check. I thing it's create an issue. If that also don't fix your query then we have to debug the code and fix it.
Please mail me at "email@example.com" for further query.
Please raise a ticket with Shopify support team.
Many people have complained about mysterious preview links.
Ideally preview links should be deactivated after sometime.
My facebook pixel has received a lot of clicks from different shopify generated URLs/preview links from 22 different 'shopifypreview' domains! This is extremely frustrating. I don't know why these domains have been generated. How can i delete them completely? I don't want my facebook pixel to track any event on different websites.