[Client, patch 7.12] Still the annoying black boxes

After ending a game, when re-queuing for another, there are still black boxes randomly replacing elements in the client's graphic during champion select; in my experience no element is immune to this (backgrounds, chat, champ portraits, etc). This bug happened in older versions of the new client as well, but is still very much present and alive. It sometimes resets and goes away after a game... I'm not sure what causes it to come and go away.