Good Morning,
Weather has been crazy lately.  Many areas have broken records for total snowfall amount, days of consecutive snow cover, and low temperatures. Snow mold, both gray and pink, were very active under all that snow cover this winter. Lawns emerged with matted turf that, in some cases, had a grayish-white or pinkish color. In most cases the snow mold didn’t actually kill the turfgrass plant, but simply blighted the leaf blades.  A light raking with a leaf rake to loosen dead leaf tissue and accelerate soil warming will help the turf recover faster. A fertilizer application in the next couple weeks will also help the turf recover and resume growth.

Another option is contacting MSU Plant Diagnostic lab. Please start by emailing your question and pictures to them. Include info such as when and how much you water, when you lasted fertilized, what other chemicals were applied and when. If they need a sod sample they will contact you. https://www.canr.msu.edu/pestid/
Using a hand lens looking at your grass blades, and comparing to the diseases here, you may be able to spot something.

Turf Diseases - Turf
As you can see, the possibilities are many, and a close examination of grass blades under magnification is usually required.

ppfs-or-t-12.pdf
The Plant Doctor: Large (Brown) Patch of Warm-Season Turfgrasses | Mississippi State University Extension Service
Go Green Lawncare Tip Sheet - MSU Extension

I hope this helps. Thanks for using our service.