I’m reasonably certain it’s the controller. I have an irrigation well with a pump switch relay (connected to the master terminal). When a zone starts, I hear the pump relay turn on, and the appropriate zone starts watering. Neither the pump relay nor zone solenoid shut off when the cycle is supposed to be done however.
This isn’t specific to one zone: it happens regardless of which one is selected. I haven’t had a chance to measure voltage on the terminals, but I’m pretty confident I’m going to find that it’s not killing power/signal to the solenoids or PSR at the end of a cycle.