Client changes resolution.

Okay so,I like to play on 1280x720 because I use OBS to record and my PC is a potato and cant handle recording + league at 1440x900(monitor resolution). I like my client on 1280x720 but after every game,my client resolution changes to 1024x576.This does not happen when I use higher resolutions.Is there a way I could keep my game resolution at 1280x720 AND my client resolution at 1280x720?