Client's Window Size keeps changing itself

I like having my client at a window size of 1280 x 720, but for some reason whenever I end a game it shows up at 1024 x 576. It gets weirder when I set it back to the 1280 where as the screen expands back to that, but the window stays at 1024. My 1st time seeing this i clicked out of the options menu thinking i fixed it only to realize the window was still tiny, and this actually prevented me from going back to the options menu because it was off screen now. Now the short term fix would restarting my client, but I shouldn't have to keep doing this just to have a window size I like. I don't even want to know what'd happen if I started on that small window to begin with. If someone at Riot is reading this, can you please iron this issue out?

Edit: Apparently the minimizing is happening when a game starts. While this also did the same for the windows of my browser, this was happening for quite a while, long before this new client. However knowing this, I can't help but think there's a link between the 2. If anyone has a fix for this, I'd really like to know, or if possible someone at riot figure this out.

Edit 2: Ok, now it's even worse. As of a few patches later (now 7.11), instead of just minimizing, 95% of it just vanishes: both invisible and un-interactive. Restarting the Client now requires me to end the task via task manager. So it upgraded from minor nuisance to real big pain. That red arrow is pointing to it. https://cdn.discordapp.com/attachments/203324860292661248/320960401254645760/My_league_of_Legends_Client_after_a_Match..png