ARAM reroll refund & Loading screen
ARAM Reroll Refund bug: 2 out of 2 times this happened, I was in a ARAM queue and I used one of my 2/2 rerolls, and a couple of seconds later a person had left the queue. When i got into my new queue, it said I had 1/2 rerolls remaining. It appears like the game wont refund your reroll when someone else leaves the queue (you usually used to loose your reroll if you were the one that left).
Loading Screen Bug: Since downloading the patch (6.24) on 7/12/16, I have with out fail, been getting "failed to connect" message when switching from client to loading screen. It is simply fixed by closing the loading screen and pressing reconnect on the client. But this happens all the time and does get quite annoying to do this process.