Hi,
You are right, there is a problem with this kind of search.
I created an issue ticket, we will investigate on the error and make a patch. Xavier, who made the biggest part of the mass action system is not here this week, he will take a look when he will come back.
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.