Hello,
Custom fields are handle by HikaShop core system.
The HikaMarket settings can't interfere with it since it call HikaShop custom field system for the display.
Best would be to report that behavior to the HikaShop support team so they can look into it.
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.