Can't access frame that is in playergui returned through remote function?

I have the remote function:

local event = game.ReplicatedStorage.Work.genhud

local function genHUD()
    local jobHUD = game.ReplicatedStorage.jobHUD
    local hud = jobHUD:Clone()
    hud.Parent = player.PlayerGui.mainHUD
    return hud
end

event.OnClientInvoke = genHUD

But whenever I call it in a server script, it says that hud is nil for some reason?

local event = game.ReplicatedStorage.Work.genhud

script.MouseButton1Click:Connect(function()

local hud = event:InvokeClient(player)
print(hud)

end)

Should I add that this event works perfectly in studio, it just doesn't work in game.