I have two Z-Wave devices connected. Both are GE brand. One is an outlet I use to control my siren the other is an outdoor switch I am trying to use to turn my Christmas lights on and off at sunrise/sunset.
I have had nothing but problems with these devices. They constantly fail. I keep removing them, adding them and then rediscover the network. They are no more than 25 feet away from the base.
I see the one labeled as the siren is communicating, however there is a malfunction listed for the other switch and it does not list any connected neighbor nodes (including the panel) which means the route has failed and the device has been unreachable.
To clarify, what is the model number of the switch are you using for the outdoor lights? Where is the switch located? (garage, front door, etc.)
There are a fair amount of failed messages counted in the panel diagnostics. Communication is hindered by distance, construction, etc. Is this an in-wall switch and has it been installed in a metal gang box by chance? If so, signaling can be heavily affected.
The best general way to boost communication in a Z-wave network is to add repeating devices between the trouble device and the panel. Z-wave devices which run on AC power function as repeaters (switches, appliance modules, etc.) which cuts the distances a signal has to travel since it can then travel from A to B to C, instead of directly from point A to point C.
GE
Z-Wave 600-Watt Outdoor Plug-In On/Off Module Switch
It works fine in the same room but then I move it outside less than 15 feet away from the control panel it fails. House is wood construction and only passes through two walls.
I assume you are referring to the GE model 12720. If the device functions near the panel but not when placed in its desired location that indicates an environmental signal issue.
The best way to boost signal in a Zwave network is to add repeating devices between. An appliance module is a good option, since it offers additional uses, or a dedicated repeater-only device could be used.
In general, the more of these devices there are, the stronger the network.