Why my function doesn't detect current speed of humanoid that triggered proximity prompt?

This is what happening: the function should detect the current walkspeed of humanoid that triggered proximity prompt, if humanoid current walkspeed at triggering the proximity prompt was 22, then the function prints "Success", else when my walkspeed is 16 the function prints "Fail", and the problem is that even when my current speed was 22 the function couldn't detect the speed correctly and prints "Fail". To change my walkspeed I use shift to sprint script. There is something wrong and I can't find the reason.

The script:

game.Workspace.Part.ProximityPrompt.Triggered:Connect(function(player)
	local humanoid = player.Character:WaitForChild("Humanoid")
	if humanoid.WalkSpeed == 22 then
		print("Success")
	else
		print("Fail")
	end
end)

Shift to sprint script: (I taked this script from youtube tutorial)

local UserInputService = game:GetService('UserInputService')
local sbar = script.Parent.SFrame.StaminaBar.Stamina
local stamina = 100
local running = false

stamina = math.clamp(stamina, 0, 100)

UserInputService.InputBegan:Connect(function(input)
	if input.KeyCode == Enum.KeyCode.LeftShift then
		running = true
		char.Humanoid.WalkSpeed = 22
		while stamina > 0 and running do
			stamina = stamina - 1.5
			sbar:TweenSize(UDim2.new(stamina/100, 0, 1, 0), 'Out', 'Linear', 0)
			wait()
			if stamina == 0 then
				char.Humanoid.WalkSpeed = 16
			end
		end
	end
end)


UserInputService.InputEnded:Connect(function(input)
	if input.KeyCode == Enum.KeyCode.LeftShift then
		running = false
		char.Humanoid.WalkSpeed = 16
		while stamina < 100 and not running do
			stamina = stamina +0.5
			sbar:TweenSize(UDim2.new(stamina/100, 0, 1, 0), 'Out', 'Linear', 0)
			wait()
			if stamina == 0 then
				char.Humanoid.WalkSpeed = 16
			end
		end
	end
end)