Hi,
I seen that issue once ; when the server have some "content" limitation on the "post" size or on the number of "post fields".
In such condition, the form is not fully submitted and some elements (which are at the end of the form) are not send ; it results that the configuration is not saved and if there is no joomla parameters (option, ctrl, task), the homepage will be displayed instead.
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.