unpack(): Type V: not enough input, need 4, have 0

[UndercoverNL]

I am using this code on a Laravel based system

        $rcon = new Rcon('ip, port, 'password', 1);
        if ($rcon->connect())
        {
            Log::info('connected');
            $rcon->sendCommand("say Hello World!");
        } else {
            Log::info('disconected');
        }

but if ($rcon->connect()) returns me the error unpack(): Type V: not enough input, need 4, have 0
which comes from

        $size_data = fread($this->socket, 4);
        $size_pack = unpack('V1size', $size_data);

But when I log all the variables inside the vendor src file, it does log the right info provided in the new Rcon.