Why wont this script allow me to change a value?

I am trying to give a player a choice to Accept or Decline a quest through the use of a GUI that starts off invisible

I am using a ModuleScript that is inside of an NPC within a folder within Workspace. e.g. game.Workspace.Folder.NPCModel.ModuleScript

I'm also using a LocalScript within a ScreenGUI inside of StarterGUI e.g. game.StarterGui.ScreenGUI.LocalScript

The LocalScript works perfectly and its purpose is to look at the ModuleScript and use the text within it as the text that goes inside of a TextLabel. The TextLabel is inside of a frame with the same parent as the LocalScript.

When I try to make a simple function to turn frame visible it doesn't work nor does it error. However when I change the function to define a variable ( frame ) and then print frame.Visible It works perfectly and tells me whether or not the frame is visible.

Then after that I tried setting frame to visible after I print whether or not it is visible. After I set frame to Visible it still doesn't become visible so I print frame.Visible again and it tells me it is visible when it is very clearly not

This is the ModuleScript where the problem is happening in

local frame = game.StarterGui.QuestGUI.DialogueHolder.Choices

local NPCLines = {
    {"What's up kid?",0.01,nil},
    {"Those bandits from the outskirts are back giving the townspeople trouble again..",0.01,nil},
    {"Why dont you go show them who they're messing with",0.01,nil},
    {"They're probably carrying some cash too",0.01,nil},
    {"You up for it?",0.01,function()
        wait(0.1)
        print(frame.Visible)
        wait(1)
        frame.Visible = true
        print(frame.Visible)
        end},
    {"Good man!",0.01, nil},
}

return NPCLines

This is the local script where the dialogue is handled

local UIS = game:GetService('UserInputService')
--local playerservice = game:GetService('Players')
--local player = playerservice.PlayerAdded << Not needed in a local script
local player = game.Players.LocalPlayer
local char = player.CharacterAdded:Wait()
local hum = char:WaitForChild('Humanoid')
local isinrange = nil
local ischatting = false
local line = 1
local istalking = false
local dialogues = nil
--local hws = hum.Walkspeed

local function onInputBegan(input,gameProcessed)
    if input.UserInputType == Enum.UserInputType.Keyboard then
        local keyPressed = input.KeyCode
        if keyPressed == Enum.KeyCode.E then
            if isinrange ~= nil and not istalking then
                if ischatting == false then
                    line = 1
                    ischatting = true
                    dialogues = require(isinrange.Lines)
                    hum.WalkSpeed = 0
                    script.Parent.DialogueHolder.Dialogue.Text = ""
                    script.Parent.DialogueHolder:TweenPosition(UDim2.new(0.5,0,0.99,0),Enum.EasingDirection.Out,Enum.EasingStyle.Back,0.5,true)
                    wait(0.5)
                    local Cline = dialogues[line]
                    istalking = true
                    for i = 1,#Cline[1] do
                        script.Parent.DialogueHolder.Dialogue.Text = string.sub(Cline[1],0,i)
                        wait(Cline[2])
                    end
                    if Cline[3]then
                        Cline[3]()
                    end
                    istalking = false
                    line = line+1
                else
                    local Cline = dialogues[line]
                    if line > #dialogues then
                        script.Parent.DialogueHolder:TweenPosition(UDim2.new(0.5,0,2,0),Enum.EasingDirection.Out,Enum.EasingStyle.Back,1.5,true)
                        hum.WalkSpeed = 16
                        dialogues = nil
                        ischatting = false
                    else
                        local Cline = dialogues[line]
                        istalking = true
                        for i = 1,#Cline[1] do
                            script.Parent.DialogueHolder.Dialogue.Text = string.sub(Cline[1],0,i)
                            wait(Cline[2])
                        end
                        if Cline[3]then
                            Cline[3]()
                        end
                        istalking = false
                        line = line+1
                    end
                end
            end

        end
    end
end

UIS.InputBegan:Connect(onInputBegan)

while true do
    wait()
    if ischatting == false then
        isinrange = nil
        for i,v in pairs(game.Workspace.QuestNPCs:GetChildren()) do
            if(char.HumanoidRootPart.Position-v.HumanoidRootPart.Position).magnitude <= 10 then
                isinrange = v
            end
        end
    end
end

UIS.InputBegan:Connect(onInputBegan)

I really don't know what to do at this point or where to even start.