My collision groups don't work on players?

Hi, I'm making a script that you can walk through other players. I can still walk through other players. What am I doing wrong?

Script:

local PhysicsService = game:GetService("PhysicsService")

local CollisionGroupName = "Players"

PhysicsService:CreateCollisionGroup(CollisionGroupName)

PhysicsService:CollisionGroupSetCollidable(CollisionGroupName, CollisionGroupName, false)

local Players = game:GetService("Players")

Players.PlayerAdded:Connect(function(Player)

    Player.CharacterAdded:Connect(function(Character)

        for _,Child in pairs(Character:GetChildren()) do

            if Child:IsA("BasePart") then

                PhysicsService:SetPartCollisionGroup(Child, CollisionGroupName)
            end
        end
    end)
end)

Script Location: ServerScriptService, a server script.