Hi,
Are you using a category listing or a vendor listing ?
The image uploaded by vendors in their vendor account is using during the vendor listing. But the images for the vendor categories are not updated, they have their own category image that you have to update.
Regards,
PS : For your HikaMarket questions, please use the HikaMarket forum section. It will be easier for everyone ans specially for me to find the HikaMarket questions and answer it.
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.