Why is my custom movement script extremely wonky?

So basically I have this script where it swaps the players body then has a movement script, however the moving is extremely wonky and doesn't work as well, aka. It's not going in correct directions sometimes and you dont move the direction you're zoomed to, help would be appreciated. Here's the script;

wait(3)
-- Declare varaibles
local userInputService = game:GetService("UserInputService")
local runService = game:GetService("RunService")
local player = workspace.test
local moveVector = Vector3.new(0,0,0)

userInputService.InputBegan:connect(function(inputObject)
    if player then
        if inputObject.KeyCode == Enum.KeyCode.A then
            moveVector = moveVector + Vector3.new(-1,0,0)
        end
        if inputObject.KeyCode == Enum.KeyCode.D then
            moveVector = moveVector + Vector3.new(1,0,0)
        end
                if inputObject.KeyCode == Enum.KeyCode.S then
            moveVector = moveVector + Vector3.new(0,0,-1)
        end
        if inputObject.KeyCode == Enum.KeyCode.W then
            moveVector = moveVector + Vector3.new(0,0,1)
        end
        if inputObject.KeyCode == Enum.KeyCode.Space then
            player.Character.Humanoid.Jump = true
        end
    end
end)

-- Handle inputEnded event (when player releases a key)
userInputService.InputEnded:connect(function(inputObject)
    if player then
        if inputObject.KeyCode == Enum.KeyCode.A then
            moveVector = moveVector + Vector3.new(1,0,0)
        end
        if inputObject.KeyCode == Enum.KeyCode.D then
            moveVector = moveVector + Vector3.new(-1,0,0)
        end
                        if inputObject.KeyCode == Enum.KeyCode.S then
            moveVector = moveVector + Vector3.new(0,0,1)
        end
        if inputObject.KeyCode == Enum.KeyCode.W then
            moveVector = moveVector + Vector3.new(0,0,-1)
        end
    end
end)

runService.RenderStepped:connect(function()
    if player then
        player.Humanoid:Move(moveVector)
    end
end)

Thanks.

Note: Game is filtering enabled, script is in ServerPlayerScripts and I want this system to be kind of like before the dawns system of forcing a player to play as a certain killer.