I have the same problem.
Sprinkler is always on in 1 zone.
I tried to change the solenoid, no help
I tried cleaning the upper part of the valve, still no use.
I tried buying a different Jar top valve and replace the top part of my sprinkler valve with the new valve attachments
Still, i have the zone 1 always water will be on, when i turn the water valve on.
Due to this i am not able to use the water system on a timer, i need to manually turn the water on and off.