Hi there. Actual computer security guy here,
League of Legends uses a client-server model. This means that all 10 players on the map, and any spectators, are connected to a central server near Chicago, IL. Players only communicate with, and have the address of, the game server. It is not possible for random players to ascertain your IP address through a League match, or through League Voice, or Discord.
You would have to voluntarily give up your IP address, or use >Skype in 2018 (or similar leaky application).
I'd bet cash money you're not getting packeted, at least not by your teams. It is possible that a single entity is spectating or monitoring your games and hitting you at that moment. But it's not your teams.