I've had a Hunter ProC system for roughly 3 years now. Everything has been fine until the last 6 months. For some unknown reason the run time programming is changing on its own. Some of the stations (not all but seems to be the higher numbered ones, later in the cycle) will change from 10 minutes to 6 hours! Has anyone seen this before?
Try rebooting your controller (unplug and remove battery or find the reset button) reprogram and see if it makes a difference. If it has a battery change that if you haven't done so in a while. Let me know. I know mostly rainbird stuff no very familiar with your controller.