Enabled value not changing for a ScreenGui in a round game, know a fix?

I tried making a round-based game that would edit each player's ScreenGui that had options to teleport around. It would cut it off for 60 seconds and cut it back on for 15 seconds.

while true do 

wait(15) 

local plrs = game.Players:GetChildren() 
for i = 1, #plrs do 
	plrs[i].Character.HumanoidRootPart.CFrame = workspace.gameSpawn.CFrame
	plrs[i].PlayerGui.tps.Enabled = false 
end

wait(60) 

local plrs = game.Players:GetChildren() 
for i = 1, #plrs do 
	plrs[i].PlayerGui.tps.Enabled = true 
end 
end

It won't turn Enabled to true or false. Anyone know the reason why?