Can you control z wave devices that are not compatible with smartthings but are with Harmony. I have a lamp module that works with Harmony but will not pair with smartthings. It’s the Intermatic HA03, Does not have the C at the end of the model.
If it’s compatible with Harmony, that would only be with their Z-Wave device, not the standard hub but the add-on thing they sell. I think you could set that as a secondary controller to SmartThings and get that setup. @JDRoberts can probably answer that more specifically. Or a custom DTH may be available for the device for ST.
I’m not aware of any Z wave devices that are not compatible with SmartThings that would be compatible with the harmony logitech extender. And the Intermatic HA03 is on the official “works with smart things” compatibility list. (The “C” shouldn’t matter in this case. As long as it’s a certified Z wave device, you can get on/off control from SmartThings.)
Almost certainly what you have run into is that you have the device set up to recognize the harmony extender as its primary controller. If you want to control it with smartthings instead, you need to exclude it from the harmony network before you can add it to the smart things network.
If you want to continue to use it with both, you can by adding the harmony Z wave controller as a secondary controller to smartthings. This will work in the sense that you will have control from both harmony and smartthings. But the statuses will not stay in sync. That will bother some people and not others.
Harmony support can help you with adding The harmony extender to smart things if you do want to go that route. Start by clicking on the SmartThings logo near the bottom right of the following page for their instructions.