A button for an elevator not working for some reason

I have no idea why this does not work, so please if you know why tell me.
Read bellow before trying to search the script for problems.

Let me explain:
This is a test script for an elevator
the last 3 lines are the 3 buttons for the elevator (A button is inside it and the other 2 are outside the elevator on the wall)

The first line where:

script.Parent.Buttons.Main.ProximityPrompt.Triggered:Connect(OnTrigger)

is the problem (probably)
So everything works except that when the elevator is up and should go down.
It works when the elevator is down and it goes up
But not working when its supposed to go down
However it works from the other buttons as it should.

Video example

local function OnTrigger()
        if IsUp == false then
            script.Parent.Buttons.Main.ProximityPrompt.Enabled = false
            script.Parent.Parent.DoorSet1.button.ProximityPrompt.Enabled = false
            script.Parent.Parent.DoorSet2.button.ProximityPrompt.Enabled = false
            goup:Play()
            goup.Completed:Connect(function()
                IsUp = true
                script.Parent.Buttons.Main.ProximityPrompt.Enabled = true
                script.Parent.Parent.DoorSet2.button.ProximityPrompt.Enabled = true
                script.Parent.Parent.DoorSet1.button.ProximityPrompt.Enabled = true
            end)
        else
            script.Parent.Buttons.Main.ProximityPrompt.Enabled = false
            script.Parent.Parent.DoorSet1.button.ProximityPrompt.Enabled = false
            script.Parent.Parent.DoorSet2.button.ProximityPrompt.Enabled = false
            godown:Play()
            godown.Completed:Connect(function()
                print("completed")
                IsUp = false
                script.Parent.Buttons.Main.ProximityPrompt.Enabled = true
                script.Parent.Parent.DoorSet2.button.ProximityPrompt.Enabled = true
                script.Parent.Parent.DoorSet1.button.ProximityPrompt.Enabled = true
            end)
        end
    end

    script.Parent.Buttons.Main.ProximityPrompt.Triggered:Connect(OnTrigger)
    script.Parent.Parent.DoorSet2.button.ProximityPrompt.Triggered:Connect(OnTrigger)
    script.Parent.Parent.DoorSet1.button.ProximityPrompt.Triggered:Connect(OnTrigger)

I thought I posted it there. My apologies.