u/Choon555

Hello, Newish lawn owner here - sod planted about a year ago. Been noticing the last couple of weeks, my yawn yellowing quite a bit. In the fall the grass was a deep lush green, but now in the spring it is yellow in patches. I’ve already gone through my spring fertilizer applications along with sea kelp and humic acid. This shouldn’t be a grub problem since I put down grub treatment as well. Is this normal because of spring weather fluctuations or could this possibly be fungus? Currently watering three times a week for a total of about 1.3 inches per week. First two pictures of the lawn are current and the last picture is of the lawn in November. So Cal / 10b. Thanks for any advice!