Problem with adding a accessory to an NPC/Player?

I am trying to add an accessory to a NPC/Player and it seems to not go on the head but to its original position. It goes on the head in normal play mode but not in a server.

I then tried adding a weld called "AccessoryWeld" and link the Part0 to Handle and then Part1 to Head. It goes on the head but not in the correct way.

Workspace > PlayerCustom > Player1 > Every thing a NPC would need

ReplicatedStorage > Character > Hats > HatName > Handle > HairAttachment TouchInterest Mesh

local playername = game.Players.LocalPlayer.Name
local hat = game.ReplicatedStorage.Character.Hats[hatname]:Clone()

local weld = Instance.new("Weld")
weld.Name = "AccessoryWeld"
weld.Parent = hat.Handle
weld.Part0 = hat.Handle
weld.Part1 = workspace.PlayerCustom[playername].Head 

hat.Parent = workspace.PlayerCustom[playername]

It successfuly adds the hat into the player, but not on the head.

It adds the weld without me doing it in play mode. But not in a server.

I have FE enabled