Funnily enough I reported a bug that was almost the same but except of the game not ending it restarted, I reported it few months ago.
Basically the match ended, as my team won the match we were given the "victory" text and then nothing, after a minute there was a pop up saying that the host left the game, afterwards 6 people, including me, excluding the bot and the host that left and caused all this, decided to leave the match that should've ended 5 minutes before we decided to leave and I was greeted with a nice matchmaking penalty and no rewards at all. I assume that the others got nothing except a penalty out of that themselves. Would be nice if this was actually looked into and fixed.
Imgur album with screenshots from the match: https://imgur.com/a/wERNt