Champion freezes, ping jumps, I'm in game without being in game?

I was playing a game with a bunch of friends and while our enemy was fighting us in our base, I got a "Attempting to Reconnect" dialog and my ping showed some ridiculous numbers (it jumped to like 700 from 30). All the champions on my screen were moving without casting anything, but their health bars were increasing and decreasing as if they were fighting. After watching this for a bit I decided disconnecting and reconnecting would solve the issue. It didn't. When I reconnected, my champion was still sitting in place along with all of the minions, but there were no other champions on the map. I was kind of just there in stasis for a very long time, until my friend messaged me that the game had ended already, so I exited the game again and ended up at score screen. Even more curiously, 3 of my teammates said they didn't even see me disconnect in the chat. Before any of these type of questions pop up: -My desktop has been running League flawlessly for the last 2.5 years, since I started playing -I have been switching mainly between two wired connections, as I've moved my computer a few times between the two places I live. Neither have given me any issues until now (if the internet connection is the issue), not since the firewall error that finally got fixed for the most part last year. -I have played about 30 or 40 games since patch 6.2 and haven't had any issues like this until now. Any suggestions as to what it could be? As far as I've seen, there hasn't been any changes in any relevant variables so I have zero clue as to what could be going on.