Why does my gui text not change back to Mute?

I want to make a music gui that changes the mute bg music/unmute bg music button. For some reason, it changes from ("Mute") to ("Unmute") but not back to ("Mute") and this is my script.

Top Half

-- variables --
local sound = game.SoundService.CustomSound
local frame = script.Parent.Settings
local ID = script.Parent.Settings.MusicID

-- open button --
script.Parent.Open.Activated:Connect(function()
	frame.Visible = true
end)

-- open button --
script.Parent.Settings.Close.Activated:Connect(function()
	frame.Visible = false
end)

-- music ID --
sound.SoundID.Value = ID.Text
sound.SoundId = sound.SoundID.Value

Important Part

-- mute music --
script.Parent.Settings.Mute.Activated:Connect(function()
	game.SoundService.PlayingSounds.Volume = 0
	script.Parent.Settings.Mute.Text = ("Unmute")
end)

-- unmute music --
script.Parent.Settings.Mute.Activated:Connect(function()
	if script.Parent.Settings.Mute.Text ~= ("Mute") then
		script.Parent.Settings.Mute.Text = ("Mute")
		game.SoundService.PlayingSounds.Volume = 0.5
	end
end)