Game opening in windowed mode

When I start a match, once per login the first match always opens in windowed mode, when I have it set to borderless. I change it in that match and it keeps it for that login. But when I exit league and login again, same issue. I tried deleting the files named game.cfg and persistedsettings.json, re-doing settings, but it still keeps occurring. What I noticed is every time I restart the client, in game.cfg: WindowMode=2 gets changed to WindowMode=1. This started with the latest client update a few days ago. Any help would be appreciated.
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