My script won't detect the Humanoid.SeatPart?

I saw the SeatPart property of the Humanoid as I needed it for my game, I'd never used it before so I experimented but it doesn't work. My local script won't print (warn) 2.

script.Parent.MouseButton1Click:Connect(function()
    local plr = game.Players.LocalPlayer
    local char = plr.Character
    if char.Humanoid.Sit == true then
        warn("1")
        if char.Humanoid.SeatPart == game.Workspace.Plots.University.Chair.University then
            warn("2")
            local study = script.Parent.Parent.Study.Text
            while char.Humanoid.SeatPart == "University" do
                wait(5)
                warn("3")
                game.ReplicatedStorage.Studies:FireServer(study)

            end
    end

    end
end)