I also experienced the same thing. I played a few games and noticed that some of my matches did not give any rating nor does it show in the matches timeline list. I hope they fix it soon since it makes ranked unplayable right now.
yes there are a couple of fourm posts about this issue. i personally have experienced this 3 times, 2 times in ranked and once in AT. the freezes during my ranked matches werent so bad as they lasted about 5-10 seconds but it still annoying as fuck. but the freeze in the AT i was in affected my entire team. we all had to restart our pcs just to get back into the match. as far as i know this bug seems to only occur in pvp matches.
this has happened to me too! twice in ranked and once in AT. during the AT incident, it was my entire team that froze, we all had to force restart our pcs just to get back into the match. i think this issue us caused by some bug in pvp matches as i never experienced freezing like this elsewhere.