Why do my remote events only sometimes get received?

Hello, im developing a game and my remote events seem to only sometimes get received i have no idea why. Im presuming its down to lag. The local script ALWAYS fires, i know this because the print statement after the fire works however, the print statement after the function on the serverscript rarely happens. Anyway, here are my scripts that use the remoteevent:

--local script:

local frame = script.Parent:WaitForChild("Main")
local Event = game.ReplicatedStorage.Events:WaitForChild("PackPicking")

frame:TweenPosition(UDim2.new(0.5, -250,0.5, -250),'Out','Quint',1)

for i = 10,0,-1 do
    wait(1)
    script.Parent.TimeTillClose.Value = i
end

frame:TweenPosition(UDim2.new(0.5, -250,-1, -250),'Out','Quint',1)
Event:FireServer(script.Parent.Main.Choice.Value)
print(script.Parent.Main.Choice.Value)

--ServerScript:

local Event = game.ReplicatedStorage.Events:WaitForChild("PackPicking")

Event.OnServerEvent:Connect(function(plr,Pack)
    print(Pack)
    local Pack = game.ReplicatedStorage.npcCategories:FindFirstChild(Pack):FindFirstChild(plr.Team.Name)
    Pack:Clone().Parent = game.ReplicatedStorage.NPCTypes   
end)

If anyone sees or knows a solution to this super annoying problem please let me know. Thanks. P.S: As an alternative would a module script work?

Also @Incapaz, this is not a request :)