Hello,
I don't think that selecting "None" will work because it will use the default tax category.
You have to select a taxcloud category which is related to the product and which will result as "no tax".
For what I remember, there were a lot of tax categories and I think there was something for gift cards and coupons.
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.