disable manipulated or customized camera?

Since these are both LocalScripts, and you only have one loop, you don't even need two scripts, you can simply combine them.

To change the CameraType, you can simply define the string, rather than write the "Enum"

The while true do loop requires a wait time (using wait(0) may break the script)

You can immediately connect the function when you define it.

The player's Character's Head is the default CFrame, so when the loop is disabled, this is what should be the new setting

local Player = game.Players.LocalPlayer
local Character = Player.Character or Player.CharacterAdded:wait()
local Camera = workspace.CurrentCamera

script.BoolValue.Value = true

game.ReplicatedStorage.Cam.OnClientEvent:Connect(function()
    script.BoolValue.Value = true
end)

game.ReplicatedStorage.Cam2.OnClientEvent:Connect(function()
    script.BoolValue.Value = false
end)

while true do
    if script.BoolValue.Value = true then
        Camera.CameraType = "Scriptable"
        Camera.CFrame = workspace.CameraPart.CFrame
    else -- Default Settings
        Camera.CameraType = "Custom"
        Camera.CFrame = Character.Head.CFrame
    end
    wait()
end

If you add a "BoolValue" -- in this case simply named "BoolValue" under the script, this will keep the loop in check --- this example has the Bool Automatically set to true.

Otherwise, if you want the loop to be broken, you can add a conditional event where upon being set by the Cam2 Client Event, the loop will break, if using the above script, you would add it under the "else" condition. This will make sure that the loop will not be run again, ever.

local Player = game.Players.LocalPlayer
local Character = Player.Character or Player.CharacterAdded:wait()
local Camera = workspace.CurrentCamera

script.BoolValue.Value = true

game.ReplicatedStorage.Cam.OnClientEvent:Connect(function()
    script.BoolValue.Value = true
end)

game.ReplicatedStorage.Cam2.OnClientEvent:Connect(function()
    script.BoolValue.Value = false
end)

while true do
    if script.BoolValue.Value = true then
        Camera.CameraType = "Scriptable"
        Camera.CFrame = workspace.CameraPart.CFrame
    else -- Default Settings
        Camera.CameraType = "Custom"
        Camera.CFrame = Character.Head.CFrame
        break
    end
    wait()
end

You can also change your loop to be a repeat loop based on a value or event

local Player = game.Players.LocalPlayer
local Character = Player.Character or Player.CharacterAdded:wait()
local Camera = workspace.CurrentCamera

script.BoolValue.Value = true
wait()

game.ReplicatedStorage.Cam.OnClientEvent:Connect(function()
    script.BoolValue.Value = true
end)

game.ReplicatedStorage.Cam2.OnClientEvent:Connect(function()
    script.BoolValue.Value = false
end)

repeat
    Camera.CameraType = "Scriptable"
    Camera.CFrame = workspace.CameraPart.CFrame
    wait()
until script.BoolValue.Value = false
-- When the loop stops, the camera defaults are reset
    Camera.CameraType = "Custom"
    Camera.CFrame = Character.Head.CFrame

However, you can also just set the settings of the camera without the loop at all like so:

local Player = game.Players.LocalPlayer
local Character = Player.Character or Player.CharacterAdded:wait()
local Camera = workspace.CurrentCamera
local part = workspace:WaitForChild("CameraPart")

Camera.CameraType = "Scriptable"
Camera.CFrame = part.CFrame

game.ReplicatedStorage.Cam.OnClientEvent:Connect(function()
    Camera.CameraType = "Scriptable"
    Camera.CFrame = workspace.CameraPart.CFrame
end)

game.ReplicatedStorage.Cam2.OnClientEvent:Connect(function()
    Camera.CameraType = "Custom"
    Camera.CFrame = Character.Head.CFrame
end)

EDIT: Comment #1, Keeping the Camera Scriptable

Remove the sections pertaining to "CameraType" but not at the beginning of the code, which changed the Type from "Custom" to "Scriptable". This can be seen below:

local Player = game.Players.LocalPlayer
local Character = Player.Character or Player.CharacterAdded:wait()
local Camera = workspace.CurrentCamera
local part = workspace:WaitForChild("CameraPart")

Camera.CameraType = "Scriptable"
Camera.CFrame = part.CFrame

game.ReplicatedStorage.Cam.OnClientEvent:Connect(function()
    Camera.CFrame = workspace.CameraPart.CFrame
end)

game.ReplicatedStorage.Cam2.OnClientEvent:Connect(function()
    Camera.CFrame = Character.Head.CFrame
end)