Did you run a Zwave Repair?
S.
When you are first starting out, you should really be concerned about working out from the hub. The 35 feet is probably a little far to ensure a good start to a strong mesh. These devices need to talk to each other.
You need to start thinking about antenna to antenna communication, not just raw distance and walls. Plug in devices are usually close to the floor. From the antenna's perspective, what is in a direct line between the plug-in device and the hub. There can be plumbing and heating inside the walls. A right-angle line between hub and device is one thing, but an oblique line will go through far more wall structure and possibly things like furniture and appliances.
Long and short here is install your first devices closer to the hub and build out.
