Wrong currency is displayed to usergroup

Hi,

The currency that will be displayed on your shop pages is set based on the "main currency" setting of the HikaShop configuration (or the geolocation plugin if you configured it).
Then, on a product page, the system will search for the prices corresponding to the current currency.
If it doesn't find any, it will load the prices of other currencies, and conver them with the currency rate you have in your currencies (menu System>Currencies).
So the system doesn't work like you want because if it did, you would end up with the possibility of customers adding products in different currencies in the same cart. And it's not possible to pay for things in different currencies at the same time.
That's why usually, online shops either force a currency, or offer you to choose a currency but don't try to have currencies per products.

Basically, what you're missing is that you need to develop a small plugin to force the current currency based on the user groups of the user. It should be just a few lines of code in the plugin.