GUI Not Getting Enabled/Disabled Until Character Reset?

The script that I made is supposed to change a text value and count down until the round starts, and the GUI afterward is supposed to disable. Though it doesn't disable until the character resets. The changing value works because I added a script with a function that whenever a value changes, so does the TextBox GUI. I tried the same function with enabling/disabling the GUI, but with no success. How would I enable/disable a GUI without having the character reset? The code I have will be attached below.

local st = game.StarterGui.RoundGUI
local stTime = st.Frame.Timer
local val = script.StartTime

while (wait(1)) do
	st.Enabled = true
	for i=5, 0, -1 do
		val.Value = i
		stTime.Text = "Starting in: "..val.Value
		wait(1)
	end
	st.Enabled = false
end