Not getting key fragments
I see some other people also complain about this and all the complaints are the same.
I got total of 4 key fragments, and since I got all of my chests (4) I haven't got a single key. It's been almost a week (5-6 days) and I've had more than 15 wins, meanwhile 3 of my friends got more than 10 keys. I'm sure that's a bug. I thought I'm just being super unlucky but I see more and more people say that after they got 4 chests they can't get a key so I don't think its just coincidence.