Hi,
I did some tests and found the issue.
It's because the system does the translation override twice in that case. One when the variant name is generated (for the display of the product name), and once when the characteristic dropdown selector is generated.
By changing the code:
if(strpos($val->characteristic_value, '<') === false)
$val->characteristic_value = hikashop_translate($val->characteristic_value);
$variant->characteristics_text .= $separator . $val->characteristic_value;
to:
$char_value = $val->characteristic_value;
if(strpos($char_value, '<') === false)
$char_value = hikashop_translate($char_value);
$variant->characteristics_text .= $separator . $char_value;
in the file administrator/components/com_hikashop/classes/product.php I was able to fix the problem.
Please do the change and it should work properly for you too.
We'll add that change on our end too.