A couple of days ago i noticed this bug https://imgur.com/kgRV3nE very often at the end of my games. The game basically bugs and does not give you a grade or mastery points, so if you need the weekly chest on a champion, do a game with it, you end up 15/0/10, you will not get a grade and you will not get the chest. I opened a thread on the LoL facebook page of my country and really a lot of people told me "Yeah this happened to me too". Today it happened to me 5 games in a row. It's really annoying especially if u're trying to get a champion to mastery 7 and need at least an S to get the token. How can i report this to a rioter?