Where do you live?

Have you used any fertilizer, insecticide, or herbicide on the lawn? And if so, did you do any of the prep or take down work in that area?

What is your watering schedule? How often and for how long do you water?

Have you parked any tools or equipment with the motor running in that area?

Do you have any windows that reflect on the ground in that area? It might seem like I'm reaching, but the grass appears to be burned or overheated. I've seen grass die from parking a car next to the grass in the same spot every day and the hot exhaust desiccated the grass.

I agree it's unlikely to be chinch bugs. They usually start next to hot concrete, not in the middle of the yard.

Looks to me like grass suffered heat burn, during heatwave. A friends' grass in Yorkshire had burned patches, very similar looking. I am born in different climate, and burnt grass with rising temperatures is something almost normal to me, unless it is in shade, watered constantly. But then, no sun, so, its 50%:50%.