If they said fescue then it probably did not include any KBG. They would have said was a mix or a shade/sun blend. It could be this brown color is a result of not getting enough fertilizer in the fall. I am an organic kind of guy and will tell you to apply 20 pounds per 1,000 square feet of alfalfa pellets (rabbit chow). Why that and not chemicals? Because it is too early for chemicals and not too early for organics. Organic are very forgiving while chemicals are not. If you goof up an organic app, no problems. If you goof up a chemical app, you could spend a lot of money restoring it. And if you like the results of the organic fert, you can always add more. If you like the results of the chemical app, you have to wait until fall to add more. Also set your mower to the highest setting (or one notch down from the top). Tall grass resists weeds much better than short grass. Tall grass also needs less water than short grass. Water deeply and infrequently. Deeply means a full inch all at one time. Infrequently means monthly in the cool months transitioning to once every 7 days in the hottest heat of summer. If you get hotter than the hottest heat, then slide it up to every 5 days, but in no case should you ever be watering daily or every other day. The idea is to allow the soil surface to dry completely while there is a deeper reservoir of moisture for the roots to draw from.

I would water 15 minutes at breakfast, lunch, and dinner. Watering in the middle of the day will not burn the grass. It will cool the grass. Water like that for a month. Then start to back off on the frequency and increase the duration until you are more toward once per week for 45 minutes to an hour (approximately 1 inch of water per week - all at one time). Are you sure the spot in the middle is not a low spot? If water is puddling under the sod, you might have a disease problem under there. Is there an obvious crown in the middle or could it be low? Not rolling may have been a mistake. Rolling is the most important thing to do once sod is down. YES! Walk all over it especially if it was not rolled down. Don't play soccer on it but walk on it.

If I understand correctly the grass looked fine for several weeks and suddenly got the various symptoms you described. Is that correct? You severely over watered for the first month and that is what led to the symptoms. The installer should have told you to water 3x per day for 10 minutes each time for the first 3-4 weeks or until the sod roots knit into to the underlying soil. Then start backing off on watering until you are watering every 5-7 days for about an hour. Even your nutgrass problem could be caused by the overwatering. It is a swamp grass and thrives with too much water. All the symptoms sound like fungal disease. The blob that looked like dog barf is commonly called dog barf fungus. It happens to be very ugly but it also happens to be harmless. You probably cannot really tell where that spot was several weeks later. The white stuff was likely powdery mildew. The blue areas were symptoms of not enough water but there are fungal diseases which cause the same symptom. The strong temptation is to add more water when that happens, but that is the wrong response. All the water goes to the fungus. How high/low are you mowing it? The installer should have also told you to mow at 4 inches (mower's highest setting). But this time of year is when you should be skipping mowing and letting the grass get up to 5 or 6 inches to endure the summer heat. Scalping fescue this time of year could be the problem for the large area that is dying. If you are mowing at less than 3 inches, then you cannot blame the installer for much of any of this.

What is 4p? Did they roll the sod down with a water filled roller? That's kind of important. Grass roots will not grow through the air to find moisture. If your soil is mushy, then it's too wet. If your soil is tan colored, then it's too dry. All it needs is for the very top surface to be moist. You should be able to walk on the sod without sinking in. Long grass is a good thing. That will help the roots. How are you watering? How often and for how long?