Why does this Custom Character script work for like 5 seconds?

so basically im making a custom character script, that replaces the player's character with my own model. The problem im having is my script only works for like 5 second before turning the character back to normal. How would i keep this permanent? This is located inside of player starter scripts. Its also a module script inside this script

wait(1)
local player
while not player do
    wait()
    player = game:GetService('Players').LocalPlayer
end
    --local face = player.Character.Head.face:Clone()
function onSpawn()
    local char = game.ReplicatedStorage.CustomCharacter:Clone()
    --local SpawnLocation = game.Workspace.SpawnLocation
    --face.Parent = char.Head
    char.Parent = workspace
    char.Name = player.Name
    --char:MoveTo(SpawnLocation.Position)

    --[[for _,v in pairs(char:GetChildren()) do
        v.BrickColor = BrickColor.new("Deep blue")
    end]]--skin color
    local prevChar = player.Character
    wait()
    player.Character = char
    prevChar:Destroy()

    if char:FindFirstChild("Humanoid") then
    char.Humanoid:Destroy()
    end
    local human = Instance.new("Humanoid", char)
    char.Archivable = false

    human.Died:connect(function()
    wait(1)
    onSpawn()
    wait(.1)
    player.Character.Humanoid.Running:connect(whenRunning)
    player.Character.Humanoid.Jumping:connect(whenJumping)
    player.Character.Humanoid.FallingDown:connect(whenFalling)
    player.Character.Humanoid.FreeFalling:connect(whenFalling)
    end)

local character = char
local animTbl = require(script.Animations)(character, character.Humanoid)
--Remove prints if they lag
local onGround = true
local prevAirType = 'grounded'
local inAirType = 'grounded'
local canPlayIdle = true
local canPlayWalk = false
local canPlayJump = false
local canPlayFall = false
function whenRunning(speed)
    prevAirType = inAirType
    inAirType = 'grounded'
    onGround = true 
    if speed > 1 then
        canPlayIdle = true
        if canPlayWalk == true then
            canPlayWalk = false
            print("walk")
            animTbl:stop('idle', character.Humanoid)
            animTbl:play('walk', character.Humanoid)        
        end
    else
        canPlayWalk = true
        if canPlayIdle == true then
            canPlayIdle = false
            print("idle")
            animTbl:stop('walk', character.Humanoid)                        
            animTbl:play('idle', character.Humanoid)
        end
    end
end
function whenFalling()
    prevAirType = inAirType
    inAirType = 'fall'
    onGround = false
end
function whenJumping()
    prevAirType = inAirType
    inAirType = 'jump'
    onGround = false
end

character.Humanoid.Running:connect(whenRunning)
character.Humanoid.FreeFalling:connect(whenFalling)
character.Humanoid.Jumping:connect(whenJumping)
end

onSpawn()

player.Character.Humanoid.Running:connect(whenRunning)
player.Character.Humanoid.Jumping:connect(whenJumping)
player.Character.Humanoid.FallingDown:connect(whenFalling)
player.Character.Humanoid.FreeFalling:connect(whenFalling)