I was recently tagged as a 'Leaver' and I believe I lost 18 LP because of it. I was wondering if there was a process to contest what happened? It honestly felt like someone was ddos-ing me. We had just forced a flash out of mid on an invade and were returning to our own jungle when I disconnected. The connectivity issues continued until the game was surrendered and 'Remade'. I don't usually have connectivity issues - ever, which made me suspicious.
You can't contest it, but you can try to find out what the issue was and fix it. It's extremely unlikely you were the target of a DoS attack.
Head over to the Connection Troubleshooting Log Reader. There, you can submit the Network logs from your match(es) and the log reader will show if you were having ping spikes and packet loss.
It will then will direct you to solutions. Please work through the solutions it suggests, and if you need assistance or they do not work post on the Help & Support board and we'll try to help.
You can also narrow down the source of latency or packet loss by downloading the WinMTR Network Diagnostic Tool, then use that to run a traceroute to the following IP (allow this to run for 5-15 minutes);
104.160.131.1
I've been having a few connectivity issues recently myself. I think I spent my last couple games stuck at 5k to 10k. Thankfully, I'd already discovered the issue in an ARAM game so those were only Beginner Bot games.
It is rather annoying.
