There are several in-the-wall GE z-wave paddle switches, at least one GE z-wave electrical outlet which I understand serve as ‘repeaters’ for the mesh network. Additionally, I also have a z-wave thermostat that should also serve that purpose. In fact, there is a GE paddle switch within about one foot of one of the door locks. The one lock that seems to function properly also has a switch very close to it. Only one of the locks has any distance to it to the next z-wave device and that isn’t more than 10 ft max.
With Nexia and its hub, it was placed about as far away from the locks as you can get in my house and they all still worked perfectly.
I also ran the repair the network from the ST app just to be sure everything was optimized with no change. The two locks that do not respond show they are locked, which they are, they just do not show battery status or respond to lock/unlock commands.