None of the zones are watering when the app says it's watering. I measured each zone when active and each read 28 AC. When testing the resistance, the readings were jumping all over the place for each reading. This is leading me to believe there is an issue with the master solenoid valve. However, there is no wire that connects to the M slot on the controller. Looking around the house for any of the underground boxes, I have not been able to find the master solenoid. Attaching pictures of what I have found. Any help greatly appreciated.