Hi,
It's not an HikaShop bug.
You have overrided the view and now your "contact" button is a submit button with some javascript input.
When you press the "enter" button, the first "submit subtton" in the form is validate and it is your contact button.
Please change your contact button into a classical button (and not a input submit) in order to fix your problem.
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.