Waiting on opponent to a "you conceded" match

This has happened twice today. Two different opponents, all with 600+ LP, game showed the "waiting on user", about 45 seconds later I get a "You conceded", which I didn't. No internet issues, it does not happen with most of users, and it's happened twice today. Is there any bug related to this? I lost my winning streak and 20 LP points twice due to this.