Getting a players shirt/pants to change from a GUI with filtering enabled?

Hello, I've been having some issues with getting my uniform giver to work correctly with filtering enabled. It only works in roblox studio, so I assume it's a filtering enabled issue, but I need my filtering to be enabled.

It works by walking up to a locker, and a GUI prompts you for what clothes you want. This is the script I have inside of each button that does not seem to be working.

local shirtId = script.Parent.Shirt.ShirtTemplate --shirt template location

function onClicked(player)


    print(player.Name.." clicked on Uniform Giver")


    local foundShirt = player.Character:FindFirstChild("Shirt") -- Tries to find Shirt
    if not foundShirt then -- if there is no shirt
        print("No shirt found, creating for "..player.Name)
        local newShirt = Instance.new("Shirt",player.Character) --creates new shirt
        newShirt.Name = "Shirt" --new shirt name is shirt
    else if foundShirt then -- if there is a shirt
        print("Shirt found, reconstructing for "..player.Name)
        player.Character.Shirt:remove() --removes shirt
        local newShirt = Instance.new("Shirt",player.Character) --creates new shirt
        newShirt.Name = "Shirt" --new shirtname is shirt
    end
    end

    player.Character.Shirt.ShirtTemplate = shirtId --changes shirt Id to the template's Id
end


script.Parent.MouseButton1Down:connect(onClicked) --calls function onclick of gui