Autofill gui minor bug even after some changes?

I am working on an autofill gui for when you type into a textbox it shows a suggestion. This isnt an error, but everytime I type random upper and lowercase letters, it always sticks to just lowercase instead of how you typed it. My code works perfectly fine, however I'd like to fix this bug.

CLIP: https://medal.tv/clips/56252105/d1337cQiLrCC

TextBox = script.Parent.TextBox
Suggestions = script.Parent.Suggestion
UIS = game:GetService("UserInputService")

function Suggestion(n)
	local names = {}
	for _,plr in pairs(game.Players:GetPlayers()) do
		n = n:lower()
		local tn = (plr.Name):lower():sub(1,#n)
		if(tn == n) then
			table.insert(names,plr.Name)
		end
	end
	if #names == 1 then
		return names[1]
	else
		return nil
	end
end

TextBox:GetPropertyChangedSignal("Text"):Connect(function()
	if string.len(TextBox.Text) >= 1 then
		local plr = Suggestion(TextBox.Text)
		if(plr) then
			if string.upper(TextBox.Text) == TextBox.Text then
				local NameUpper = string.upper(plr)
				Suggestions.Text = NameUpper
			elseif string.lower(TextBox.Text) == TextBox.Text then
				local NameLower = string.lower(plr)
				Suggestions.Text = NameLower
			else
				Suggestions.Text = plr
			end
		elseif plr == nil then
			Suggestions.Text = ("")
		end
	else
		Suggestions.Text = ("")
	end
end)

UIS.InputBegan:connect(function(i,gps)
	if not gps then return end
	if i.KeyCode == Enum.KeyCode.Return then
		local plr = Suggestion(TextBox.Text)
		if (plr) then
			TextBox.Text = plr
			print("Successfully autofilled.")
		end
	end
end)

Nevermind, I already got it to work after adding a few more strings to it.