[votan]

Originally Posted by ZOS_ChipHilseberg Looks like we were able to reproduce it.

Thanks @Chip.

I already took a look into the issue and may save you time.
The problem is distributed across two source files. At the end the code for the summary and the code for the sub-category are calling the same function: self:GetCategoryInfo(categoryIndex)
To get the correct values for what you call yourself a faked sub-category=General, is to substract all real sub-category values from the summary values.
Like this:

do
    local orgGetCategoryInfoFromData = ACHIEVEMENTS.GetCategoryInfoFromData
    function ACHIEVEMENTS.GetCategoryInfoFromData(self, data, parentData)
        if not data.isFakedSubcategory and parentData then
            return orgGetCategoryInfoFromData(self, data, parentData)
        else
            local numSubCategories, numAchievements, earnedPoints, totalPoints, hidesPoints = select(2, self:GetCategoryInfo(data.categoryIndex))
            if parentData then
                for index = 1, numSubCategories do
                    local subEarned, subTotal = select(3, self:GetSubCategoryInfo(parentData.categoryIndex, index))
                    earnedPoints, totalPoints = earnedPoints - subEarned, totalPoints - subTotal
                end
            end
            return numAchievements, earnedPoints, totalPoints, hidesPoints
        end
    end
end