After a few games I played today in AR URF mode I didn't get any rewards except for IP.
My mastery level bar seems to be loading forever and I couldn't get chests, key fragments nor champion mastery (despite the fact I did very well). 
Riot please fix this!
I am really looking forward to spending my whole weekend playing the best mode ever 
Wtf urf is out ?
I have exactly the same problem, i dont get any mastery stuff for it, for example i jsut played mundo fist time again this season, got 12/1 score on him, but if i click on my collection, it still sais i never played him....
https://support.riotgames.com/hc/en-us/articles/204211284-Champion-Mastery-Guide this says it should, sux that it doesnt but for master 6 and 7, the game modes dont work, so what was ur mastery for the champ u played?
