Hello,
Your serials are not consumable serials (as you can see in the second screenshot).
But your serials are "also" HikaShop coupon (since you're using the coupon generator).
So your issue is not with the configuration of the serials nor the consumption of serials.
You're not consuming serials, you are trying to use HikaShop coupon which do not have a usage limitation.
So you should fix the configuration of the coupon template and, see to also modify your generated coupons to also set the usage restriction.
These are HikaShop related stuff.
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.