GoControl GC-TBZ48 Z-Wave Thermostat Devouring Batteries

I have a half-dozen of these happily controlling heating zones in my home. But recently, two of these units have begun to absolutely DEVOUR batteries. A set of four AA batteries was typically lasting through a heating season. But, now, on these two units, they’re going down in two weeks. I switched to an Aeotec hub this summer - could that be causing increased Z-Wave communications? But why on only SOME of the thermostats? Is there some setting I’ve botched? Ideas?