My collection of Z Wave devices seems to be behaving well, with one exception.
I have a Fibaro FGFS-101 ZW5 Flood Sensor that runs for a while and then is reported as being offline. This particular sensor is actually one of the closer devices to my Smart Things Hub. I have fitted it with an external 12V power supply. I’m not sure what to do to keep it online. I have another of these devices a bit further away from my hub and that one is battery controlled. It doesn’t exhibit any problems. I have a pair of First Alert Z-Wave smoke detectors, battery operated, that don’t have problems. I’ve also got a few Aeotec Multisensor 6 devices that are operating without difficulty, as is a smart lock that’s battery operated.