Hi,
You have two different urls because it is not the same page.
In the Joomla way, you created three menus items.
For each menu item you can configure Joomla modules, template etc. It means that each menu, each page is different.
So that is logical that the url are different.
You have several possibilities.
1 - Use the "canonical url". It will be very useful for the SEO. Only the canonical url will be use for the SEO so the "clones" won't be browse or analyzed by the bots.
2 - Use "alias SEF" feature of your SEF extension.
You can use both, they are not incompatible.
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.