stuck zone
so two things cause stuck zones,faulty clock sending voltage while off,in which case unplugging clock shuts it off. yours must be the other cause which is water shuts it off. the best way to find the correct zone,in the box when the valve is stuck,turn on another zone, if all the water is comming out of that 1 stuck valve,and then you bleed on another valve that isnt stuck,the pressure will drop on the sticking zone,because now your sending some of the stuck zones water out another source. so if you opened up the valve box and saw 5 valves, and 1 of them is stuck,you turn on a zone while the stuck zone is on,and the pressure drops on the stuck one,then thats not the valve,you shut that one,turn on the next one in line pressure drops,not it,turn on the next one and the pressure stays the same on the stuck one or increases,this is your zone. shut off main,bleed on a few valves to get rid of water in main line,probably a good idea too just in case you do have the right zone,dig out from around all the valves so you can open the valve up,and turn the main on for like 1 second to flush anything out,your not opening the valve with the water on so there could be a rock in there,it just keeps falling into valve body or pipe once water is off.
find the valve that doesnt make the pressure drop on the stuck zone and that is definately your bad valve,or valve with a rock in it. change it out and your all set.