Fullscreen setting keeps resetting

Seemingly at random, but as often as daily, the fullscreen/window setting keeps bugging out.

I start the game menu, it starts in some strange window resolution which doesn't cover top part of the screen.
I check the settings, both "Ingame/Menu Display Mode" are set to "Fullscreen".
Starting a game match does not fix the problem.
Only way to fix this is to set one of the settings to "Windowed" and then again to "Fullscreen".

I have the same problem.
Even though it says that it's on "Fullscreen", if you click on it and click on Fullscreen, it actually goes to Fullscreen for real. That's how it works for me, anyway, but it might work for everyone else as well. Not a very big solution but it might save you a click or two.

quote: if you click on it and click on Fullscreen, it actually goes to Fullscreen for real

Actually saved me a lot of time, great trick.