Why does it only work when I play by myself?(unanswered)

I have two separate pieces of script here. Basically it displays a message if the team "survivors" has no players left(waitforwinner function). It works only when a single player is on but when I tried to play with someone who else at the same time it failed to display the message

function Waitforwinner()    
wait(420)
if #getTeam(game.Teams.Survivors) >= 1  then
local m = Instance.new("Message", Workspace)
m.Text = "Time has run out. Survivors win!"
wait(3)
m:Destroy()

for i,v in pairs(game.Players:GetPlayers()) do
            v.Character.Humanoid.Health = 0
            v.TeamColor = BrickColor.new("Bright blue")
            wait(5)         
            v.Character.Humanoid.WalkSpeed = 0
        begin("Beginning the round now!You will have 15 seconds before a player is randomly infected.",3)--function begin
        respawn()
        FirstInfected("A player has been randomly infected!",3)
        waitforwinner()
        waitForWinner()
end
end
end

function waitforwinner()
if #getTeam(game.Teams.Survivors) == 0 then
        m = Instance.new("Message",Workspace)
            m.Text = "The final survivor was infected. Once you respawn the round will begin!"
        wait(3)
    m:Destroy()         
        for i,v in pairs(game.Players:GetPlayers()) do
            if v.TeamColor == BrickColor.new("Bright orange") then
            v.StarterGear.Revolver:remove()
        end
            v.Character.Humanoid.Health = 0
            wait(1)
            v.TeamColor = BrickColor.new("Bright blue")
            wait(5)         
        begin("The round has begun.",3)
        GiveGun()
        FirstInfected("A player has been randomly infected!",3)
        waitforwinner()
        waitForWinner()
        end
        end
end

waitforwinner()
waitForWinner()

Any reasons why this wouldn't work? Thanks