I'm having issues with Sound in my game, can you help please?

I'm trying to add Lobby and Game music to my new game - 'Ray Catcher' - title work in progress, but for some reason, the lobby music keeps cutting off, and not changing to a new song. All the songs are in a folder in Workspace, one folder for game music, one for lobby music, but I'm only able to test LobbyMusic at the moment.

-- this is repeated every second
if not CurrentLobbySong or not CurrentLobbySong.IsPlaying then
    print("1", CurrentLobbySong)
    if CurrentGameSong then
        print("2", CurrentGameSong)
    else
        print("3",CurrentLobbySong,CurrentGameSong)
        local t = 1
        repeat
            newSong = lobbyMusic[math.random(1,#lobbyMusic)]
            t = t - 1/30
            wait()
        until t < 0 or newSong ~= CurrentLobbySong
        CurrentLobbySong = newSong
        CurrentLobbySong.Stopped:connect(function()
            CurrentLobbySong = nil
        end)
        CurrentLobbySong.Ended:connect(function()
            CurrentLobbySong = nil
        end)
        CurrentLobbySong:Play()
        print("4",CurrentLobbySong,CurrentGameSong)
    end
else
    print("5",CurrentLobbySong,CurrentGameSong)
end

This is in a Server Script, and it works fine in Test mode, but when I play it online, it recognises 'CurrentLobbySong' is a song, will show IsPlaying as true, but the TimePosition doesn't update, nor does TimeLength, even though the music is playing. Even when the music stops online, it won't call the Stopped/Ended function.

Any help or knowledge in this area would be most appreciated.