Thatās not how zwave works per the independent third-party standard, so there isnāt really anything smartthings can do about it. The devices decide for themselves what their best route to the hub will be, using a lot of information that is not available to us.
The one thing you can do is to run a āZ wave repair utilityā when you add a new device. That will force your devices to reevaluate all their neighbors and choose the best route based on whatās available.
All of that said, itās really important to understand that zwave is not like Wi-Fi: the so-called ārange extendersā donāt really do anything different than any other Mains powered Z Wave device would do in the same physical location, like a light switch or a smart plug. They were important back in the third or fourth generation of zwave, but now that SmartThings is into generation five and most other Z wave hubs are in generation seven or eight, you just donāt need the single use extenders anymore. However, if you donāt happen to have any other mains powered Z wave devices nearby, that can be helpful.
With locks, though, the most important thing is that you have a mains powered device that supports ābeamingā within about 15 feet of the lock. This will act as a kind of answering service for the battery powered lock and help make sure it gets its messages to and from the hub most efficiently.
See the following thread for details
FAQ: why would I need another beaming repeater if my zwave lock is already close to my hub?
Your Z wave extender itself probably does support beaming, so it may be that the best thing is just to move it close to the lock if you donāt have any other mains powered zwave devices nearby.
After youāve moved it physically to its new location, you either need to wait a couple of days for the lock to figure out the new neighbor, or go ahead and run the Z wave repair.
Itās definitely frustrating that smartthings doesnāt give us the kind of network mapping utilities that most Z wave hubs do, but they just donāt. So we are kind of operating blind here, and just have to try some trial and error.
If you havenāt read it before, you might want to take a quick look at the wireless range and repeaters FAQ, as that can be helpful. Zwave and Zigbee are mesh protocols, very low power, which is useful because it lets us have a lot of battery powered devices that just wouldnāt be practical if they used Wi-Fi, but a mesh network does work differently than Wi-Fi does, and it can take a little getting used to.
Start out by reading post 11 in the following FAQ (I will link directly to that post), then go up to the top of the thread and read down from the top, and you should learn most of what you need to know to build an efficient Z wave network.
A Guide to Wireless Range & Repeaters - #11 by JDRoberts
