I only played one game today, so I'm not sure how widespread this is, but after winning a 15 minute ARAM, and honoring a teammate, I came out to the post-game stats screen and received a grand total of +0 XP (it actually said that amount), and neither the champ mastery points or the champ rank were even visible.
I enjoy playing different champs in ARAM, and leveling up their mastery (currently a total of 402 champ mastery points), and it would be kind of nice to expect that if I play well and should receive an S, I could still receive a hextech chest. Also, leveling up and getting more BE would be alright with me.
I know that for some, playing the game is its own reward, but I think the rewards are kind of rewarding too.
Has anyone else besides myself (and according to post-game chat, at least 2 of my opponents in that game) seen this bug?