problem with first user access

-- HikaShop version -- : 2.5.0
-- Joomla version -- : 3.4.3
-- PHP version -- : 5.5.12

Hi! i've a problem with new user registration. After new registration (for registration browser point to /hikashop-menu-for-categories-listing/user/form), after user confirm via email, when user try to login, it fail (user not exist or password wrong). As admin i view the new user correctly created: moreover if user reset his password or i modify it as admin, the issue is solved.
Is possible that the user registration using hikashop module have some problem to store password in joomla? in effect after modify password using joomla, the user login correctly
how can i resove this issue?

regarding
Roberto

UPDATE: i try to match the plain text password (that i use for registration) and the bcrypt hash saved in joomla user table (profix_user). it not match! How is it possible? i'm very worried of solve this issue...
txn
with regard
Roberto