Hi,
There is nothing in HikaShop which adds a 0 amount fee labeled "-1" by itself to the cart. As I said, additional fees are usually added by plugins. Or it could also be a tax rule with the "cumulative tax" setting activated and its tax rate labeled as "-1" and its rate being 0, or maybe it's tax rate being deleted.
An update can't do any of that by itself.
I already told you what I need to know in order to understand the situation. I need to know
the details of how you configured your tax rules, your shipping fees, your payment fees, and tax settings in the HikaShop configuration
Only by understanding the situation can we look at finding a solution.
Maybe the simplest would be for you to provide a backend access to check things out directly ? If so, you can provide the access via our contact form with the URL of this thread as reference:
www.hikashop.com/support/contact-us.html