St. Augustine Brown Spots

My gardner contacted me to let me know that some brown spots have appeared on my back lawn. The lawn is St. Augustine and receive full sunlight at mid-day (shaded from early & late day sun). Florida has received alot of rain as of late (but this is not standing water area). Further the lawn receive very early morning irrigation.

Can someone help me determine if this is fungal or pest issues? If it's fungal will the corn meal treatment work? If it is pest... any suggestions?

Any help is appreciated. Thank you.

Ps. I have been away for about 3 months so I can not tell you anymore that what has been provided. Will be onsite this upcoming weekend and can possibly answer further questions at that time.