I believe you may have insect damage to your lawn.  I used the key provided by NCSU, https://ncturfbugs.wordpress.ncsu.edu/resources/key-to-turfgrass-insect-damage/, and came up w/ a few possibilities: ground pearls, https://www.turffiles.ncsu.edu/insects/ground-pearls-in-turf/; mole crickets, https://www.turffiles.ncsu.edu/insects/mole-cricket-in-turf/; or possibly grubs or caterpillars.  But I realized that it will take closer inspection of your lawn to determine the cause.  I suggest you use the key linked above and carefully inspect your lawn as you go through the key to get to the correct determination.  The key will take you to further links that will give more information about specific insects and provide control information.

Good luck!