Hi, your question is very similar to the one @underlock asks in his post but he asks from silver to gold, what happened to you is that you went up to the silver league and possibly stayed in the bronze league and to obtain a league chest silver you need to earn more in the bronze league. It is recommended that if you went up to the silver league you should get to that league as soon as possible. So you can win more chests, you must reach silver 1 in order to easily get chests from that league.