Hi,
At this moment, you can't have a "free shipping" everytime.
You have to change the way that your shipping configurations restriction are made in order to do not accept the "free shipping" for some products.
Maybe with the "weight" if your products does not have one.
In the next big version of HikaShop, the shipping system will be highly improved with the "multi shipping" system.
It will allow you to create some shipping groups. But for the moment, this release (and this feature) is not completely finished.
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.