I think ROBLOX released an update to the camera of some kind because before, these scripts worked perfectly fine. Upon joining a game, the player's camera would be fixed to an object.

The OnEnter script in the Workspace:

game.Players.PlayerAdded:connect(function(player)
	--Setting the player to the side for now
	local character = player.CharacterAdded:wait()
	character.HumanoidRootPart.CFrame = CFrame.new(Vector3.new(1000, 1000, 1000))
	character.HumanoidRootPart.Anchored = true
	
	--Setting the camera
	local camScript = game.ServerStorage.IntroCamera:Clone() --The IntroCamera script is shown in the script below this one
	local backpack = player:WaitForChild("Backpack")
	camScript.Parent = backpack
	camScript.Disabled = false
end)

The IntroCamera script that is inserted in the player's backpack:

cam = game.Workspace.CurrentCamera
target = game.Workspace.IntroCamera

cam.CameraSubject = target --Camera is pinned to a part in the Workspace
cam.CameraType = "Scriptable"
cam.CFrame = target.CFrame

The purpose of this is to set up a menu for the player to interact with. The player would be able to click Play or Options, things like that. However, going back to recent changes I noticed to the camera, the mouse is no longer able to move once the player's camera is fixed to the part. It's just fixed to the center of the screen. Why would ROBLOX add this change? Does anyone know how I can disable it?