Why is ClassicChat not working?

I have done this many times in the past yet for some reason its not working anymore, I’m referring to the ClassicChat value. I have used the same method to try and add the old bubble chat, but for some reason its just not working???

Can someone please help?
Screenshot (1983)
Screenshot (1984)

Read this here.

You can do this without forking chat settings, please take a second to read.

A script to change to change to the chat which is a LocalScript in ReplicatedStorage in the forum.

local Chat = game:GetService("Chat")

Chat:RegisterChatCallback(Enum.ChatCallbackType.OnCreatingChatWindow, function()
    return {
        ClassicChatEnabled = true,
        BubbleChatEnabled = false,
    }
end)

If this incorrect, just look further into the DevForum.