Hi,
We fixed several things in the "zone" custom fields system, it is possible that we fixed the problem you have.
If you want to send us an access to your store, we can see to install a preview version of HikaShop 2.2.2 and see if the problem is right fixed.
HikaShop 2.2.2 is currently in test in our side, we want to release it before the end of the month.
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.