Hello,
I performed some test and I couldn't reproduce your issue.
We can see that you're using the legacy "add to cart" and also the legacy "checkout" systems.
These can be an element of your problem. You can try to deactivate the legacy settings in the HikaShop configuration :
www.hikashop.com/support/documentation/5...html#advanced_legacy
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.