Can't use my native aspect ratio?

I have a 27" 2560 x 1440 res monitor. I’ve been playing on it for a while and I noticed that the scaling seems off in Overwatch. Input lag, hit reg, Crosshair is big and blurry, UI, etc.

I asked support about it and they told me that 2560 x 1440 resolutions are meant to be played using the 21:9 aspect ratio in Overwatch.

But my monitor isn’t a widescreen and it’s native aspect ratio is 16:9. So if I use the "recommended’ Aspect ratio- everything LOOKS better but the input lag/sens feel wrong still. And then I have the black bars around the top and bottom of the game.

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