Just today my client started automatically switching from the regular 1280 x 720 size to the smaller 1024 x 576 and I don't know why. It happens after every game. Also when I switch back to 1280 x 720 I have to go back and forth from 1024 x 576 twice or it will stay as a 1024 x 576 size window but the text and images will be as if it were the 1280 x 720 size which makes the settings inaccessible and I have to restart the client.
This board is the best place to discuss the client with Rioters and your fellow players, although it won't be our main source for feedback resolution. Look to the other tools, like the Submit Feedback button in the client, for that. As always, please follow the Universal Rules and keep content focused on appropriate topics for this board.