I think you have multiple issues going on, related to both Irrigation and soil fertility.
Looking at those pictures and it’s very apparent that your soil is too dry. On average how many minutes a zone were running and how often? How about head spacing? Are you on a well or municipal water? Nozzles? How many heads on a zone? How about a rain sensor? Do you have one properly placed and working? Or, are you relying on Rachio to do it.
Now on to soil. What’s your pH? How about potassium levels? How much N do you put down? Cation exchange capacity? How thick in inches is your topsoil layer? Was it brought in recently? Any compaction? Can I easily get a soil probe into the ground.
Now on to cultural. Are you taking into account the trees and shrubs in or adjacent to your lawn zones? They will suck up most, if not all, the water you budgeted for lawn.
Soil moisture sensors are a great addition to any system, but you really need to know the answers to all of the above.
If you don’t know, how is a computer in Colorado supposed to?
If you want to discuss further, send me a pm. I am on LI and I do this for a living and would be more than happy to help you out.