Why does this block for welding work on only one player?

	part = Instance.new("Part", workspace)
	weld = Instance.new("Weld", part)
	weld.Part0 = part
	weld.Part1 = workspace[playername]["Torso"]

I have tried using multiple different weld scripts to try to make this work but it only works with my player in studio and not in the game, and it does not work for anyone else in the studio, i can confirm playername is not a nil variable.

game.Players.PlayerAdded:connect(function(player)
    local leaderstats = Instance.new("Model") 
    leaderstats.Name = "leaderstats"
    leaderstats.Parent = player

	local money = Instance.new("IntValue")
	money.Name = "Money"
	money.Value = 0
	money.Parent = leaderstats
	
	local grass = Instance.new("IntValue")
	grass.Name = "Grass"
	grass.Value = 0
	grass.Parent = leaderstats
	
	local playername = player.Name
	game.Workspace.superimportantstuff.Player.Value = (playername)
	
	part = Instance.new("Part", workspace)
	weld = Instance.new("Weld", part)
	weld.Part0 = part
	weld.Part1 = workspace[playername]["Torso"]
	
	local Lawnmower1 = game.ReplicatedStorage.Lawnmower1:Clone()
	--Lawnmower1.Parent = player.BackPack
	--Lawnmower1.Parent = player.StarterGear
end)