I have this exact same problem. We went away for a few days during a heat wave without realizing the problem and not having internet access so we lost several shrubs as a result. Smart watering had been working fine for weeks and now won’t schedule watering for any zone regardless of continued high temperatures and 0% moisture status. Also noticed a new strange behavior. When selecting a zone, instead of counting up from 0% to whatever the current moisture level is, it starts counting up from a large negative number like -1350% until it gets to zero then stops.
We are having to either manually start the zones or set manual programs. Double checked all settings. Everything is as it was when the system was working.
Hogans, did they ever fix your problem? If so, how?
Please and thank you!