So, I was trying to include a secure battery device on my C-7...
My first attempts were where the device was to be located. Note to self: bring the device to the hub, or the hub to the device because otherwise pairing will not complete.
So, having tested inclusion with my test hub, I went to include with my production hub. Attempt to include... no response. Reboot the hub. Try again. What happens next is bizarre...
The Device Discover page responded with a spree of 37 "Found Z-Wave Device" messages. All the node IDs are devices that have previously been (successfully) included.
I'm guessing here, but I think that message comes from the boot activity of checking the Radio's DB to the internal DB. It found devices out on the Radio that weren't in the Internal and 'fixed that' perhaps??
Device Discovery > Z-Wave > Start Z-Wave Inclusion, immediately following a reboot. It didn't happen yesterday, so something has changed. Unfortunately I don't know what it is. I haven't been able to include anything new since it started.
I'm running another repair to see if that clears it.
This is not related to your other issue, but it's probably worth mentioning anyway: you shouldn't need to do this, at least not for Z-Wave Plus devices ("classic" Z-Wave can't pair via the mesh, so you may have to do that in this case). In fact, if they can't pair in place, they probably won't work in place either, since that would likely be an indicator of an insufficient mesh.
What may happen if the device doesn't seem to pair easily, however, is that it goes to "sleep" too soon before S2 pairing completes. I've been told that "waking" the device after entering the DSK may help with this, though I'm not sure if that means attempting to re-enter inclusion mode on the device or doing the "wake up" procedure (often a specific button-tap pattern on the device), though my guess is the former since they mentioned something about the device's NIF needing to be resent. (This would be what staff told me on an older hub firmware version; it may have gotten more robust since then, and I hope it does in the future.)
I think it's associated with security negotiation on the C-7. They paired in place and worked for a year with the C-5. They're only 50 feet or so from the hub. One hop. But that one hop appears to be enough to kill the security negotiation. Been that way with all secure devices I've tried so far.
I've also run the include with the battery powered devices several times on my test hub (no hops) and the include has been successful each time.