Please define "enough water." How much and how often?

Lawns don't get viruses, so this is a fungal disease. The problem with many zoysia varieties is that they do not come back from a setback like this. I have had zoysia and will never have it again. If you spend a lot of money spraying fungicides, then next April the area will return to normal. If you spend no money, then next April the area will return to normal. But you always live on the edge thinking, is it going to get diseased again this year. One of my old neighbors used to pay to have his annual dead spot cut out and replaced with new sod. There are many different varieties of zoysia, so yours might return.

Again, how much water is it getting?

Also, is there any reason to think that area might be a low spot that holds water longer or that other parts of the yard drain through?

The spot is on a very slight downward slope so I think it has decent drainage there.

I can see some green grass starting to grow in there after the lawn care company sprayed, but not a whole lot. We have sprinklers twice a week and it's been raining enough. The amount of water is probably just right.

Urgh, if I knew Zoysia has a fungus problem we would have opted for something else. I hate spraying all that stuff on it ! Darn it.

What type of grass doesn't have fungus problems?

"What type of grass doesn't have fungus problems?"

Maybe try astroturf? j/k Seems like there are some southern warm season grasses that are bulletproof. Centipede? I'm not expert on those kinds of lawns though.

OK, so what exactly should we spray on this fungus? It's not like we can change this grass any time soon.

Should we be doing anything else between the visits from the lawn care service?

It is probably corona virus, since it is appearing every where these days ;-)

I had the same exact thing happen to our sod at 4 weeks when I started to lessen the amount of watering. The "patches" started off as 1 or 2 then slowly spread. We called the place we bought our sod and they sent the sod rep to our house. (A small nursery with great customer service!) He took 1 look & immediately said it was not being watered enough! (I too thought it was a fungus.) You should be able to put a screwdriver into the sod & it should be able to easily go down 6 inches. (He had a fancy gadget, stabbed it into the soil to get a soil sample. When the sample came up, it was crumbled & dried. He said the screwdriver test works as good.) Unfortunately for me, it was too late as those patches had spread everywhere & there was no coming back. I thought the sod guy was trying to hustle me so I called a friend's friend who worked for the county, he also said it was due to under-watering. Our sod was Kentucky Bluegrass. I posted my photo on here too & 2 people said it looked like fungus. Maybe yours is but maybe it isn't? I just wanted to share my story. I wish I had saved my photos.

Underwatering, overwatering, and disease all look the same in zoysia. The screwdriver test is a good one.

pull some of the grass up and check the soil. It could be Japanese beetle larvae. These guys can be treated naturally with nematodes.